Glazecalc

com.glazecalcapp/glazecalcVersion 1.4.0

Ceramic glaze chemistry: unity formulas, limit checks, substitutes, cones and potters' guides.

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Claude Code

claude mcp add --transport http glazecalc https://glazecalcapp.com/mcp

Claude Desktop and claude.ai

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Settings > Connectors > Add custom connector
Name: glazecalc
Remote MCP server URL: https://glazecalcapp.com/mcp

Cursor

{
  "mcpServers": {
    "glazecalc": {
      "url": "https://glazecalcapp.com/mcp"
    }
  }
}

VS Code

code --add-mcp '{"name":"glazecalc","type":"http","url":"https://glazecalcapp.com/mcp"}'

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Tools

34 tools

Tools of Glazecalc
	Description		Read-only	Idempotent	Open world
`add_firing_rows`Adds rows to the end of one of your firing logs (an id from list_firings), in the log's own columns (get_firing gives them): the readings dictated during a firing. The rows already there stay as they are, and the log as it was is kept as an earlier version. At most 500 rows a log. Save only what the person said and agreed to; never fill in an amount, temperature or analysis they did not give. Needs an access token that can read and change your records.	Adds rows to the end of one of your firing logs (an id from list_firings), in the log's own columns (get_firing gives them): the readings dictated during a firing. The rows already there stay as they are, and the log as it was is kept as an earlier version. At most 500 rows a log. Save only what the person said and agreed to; never fill in an amount, temperature or analysis they did not give. Needs an access token that can read and change your records.	Yes	No	No	No
`add_my_material`Saves a material of your own in your Glazecalc account (the Materials page) from its oxide analysis in weight percent, as on a data sheet, with its loss on ignition. Recipes can then use it by name. Needs an access token that can read and change your records.	Saves a material of your own in your Glazecalc account (the Materials page) from its oxide analysis in weight percent, as on a data sheet, with its loss on ignition. Recipes can then use it by name. Needs an access token that can read and change your records.	No	No	No	No
`add_notebook_entry`Adds an entry to your Glazecalc notebook (the Notebook page), with an optional title: a test result, an observation, a firing to try. With about, it is a note about one of your recipes, materials or firing logs, which list_notes finds by that record's id. Needs an access token that can read and change your records.	Adds an entry to your Glazecalc notebook (the Notebook page), with an optional title: a test result, an observation, a firing to try. With about, it is a note about one of your recipes, materials or firing logs, which list_notes finds by that record's id. Needs an access token that can read and change your records.	No	No	No	No
`add_to_shelf`Marks materials as on hand (the shelf that Match with what I have uses), by the library's names or your own materials'. The shelf as it was is kept: undo_shelf_change puts it back. Needs an access token that can read and change your records.	Marks materials as on hand (the shelf that Match with what I have uses), by the library's names or your own materials'. The shelf as it was is kept: undo_shelf_change puts it back. Needs an access token that can read and change your records.	No	No	No	No
`analyze_recipe`Works out a glaze recipe's unity (Seger) formula, oxide groups, silica to alumina ratio, fired analysis, loss on ignition and calculated thermal expansion, as the Glazecalc app does. stull says where the recipe sits on Stull's chart (1912, as the recipe page draws it): silica and alumina in moles, the region (unfused, matte, semi-matte, bright or underfired) and whether it falls in the crazed area; a guide to the surface, not a promise. Stull fired his tests at about cone 11 with fixed fluxes, so at other cones, with boron or with other fluxes the regions move, and the crazed area is not a test of fit on your clay.	Works out a glaze recipe's unity (Seger) formula, oxide groups, silica to alumina ratio, fired analysis, loss on ignition and calculated thermal expansion, as the Glazecalc app does. stull says where the recipe sits on Stull's chart (1912, as the recipe page draws it): silica and alumina in moles, the region (unfused, matte, semi-matte, bright or underfired) and whether it falls in the crazed area; a guide to the surface, not a promise. Stull fired his tests at about cone 11 with fixed fluxes, so at other cones, with boron or with other fluxes the regions move, and the crazed area is not a test of fit on your clay.	No	Yes	Yes	No
`blend_recipes`Works out the test tiles of a line blend between recipes a and b (2 to 11 steps), or of a triaxial blend when c is given too (2 to 6 rows, up to 21 tiles), as the Blends page of the Glazecalc app does. Each tile is a mix of the corner recipes, each taken as a percent of its base: its shares, its recipe in percent, its key unity formula figures (silica, alumina, boron, the fluxes), silica to alumina, calculated expansion, its place on the Stull chart (stull), the names of the limit cautions it has, and, with a firing, whether its chemistry fits that firing (coneFit verdict). With two recipes and steps 2 it compares them oxide by oxide (differences). Give base materials only, no colorants. This is a calculation from published figures, not a test result: the tiles, fired, decide, and the cautions are guides, not a guarantee of food safety.	Works out the test tiles of a line blend between recipes a and b (2 to 11 steps), or of a triaxial blend when c is given too (2 to 6 rows, up to 21 tiles), as the Blends page of the Glazecalc app does. Each tile is a mix of the corner recipes, each taken as a percent of its base: its shares, its recipe in percent, its key unity formula figures (silica, alumina, boron, the fluxes), silica to alumina, calculated expansion, its place on the Stull chart (stull), the names of the limit cautions it has, and, with a firing, whether its chemistry fits that firing (coneFit verdict). With two recipes and steps 2 it compares them oxide by oxide (differences). Give base materials only, no colorants. This is a calculation from published figures, not a test result: the tiles, fired, decide, and the cautions are guides, not a guarantee of food safety.	No	Yes	Yes	No
`check_limits`Checks a glaze recipe for what is past a recommended limit for its firing (too much boron or alkali, too little alumina, too little or too much clay, rising expansion...) and says what the fired glaze will likely do, as the Glazecalc app does. A cone is checked in the band the recipe page gives it (low cone 06-02, mid 1-7, high 8-11); from cone 12 up (band 'top') no published limits reach, so the band's limits are not checked and limitsNote says so. With a firing, coneFit says whether the chemistry looks like that firing's, by Katz's boron rule and Hesselberth & Roy's silica and alumina whatever limit set is chosen: verdict 'cooler' or 'hotter' only when boron and silica or alumina agree on another band; 'fits' (nothing points away, not a pass); 'skipped' where the published figures do not reach (lead, lithium, much soda and potash or zinc, raku, cones 01 to 3, cooler than cone 06 or hotter than cone 10...). Cone 6 against cone 10 is told apart only roughly (strength 'soft'). stull says where the recipe sits on Stull's chart, as analyze_recipe gives it; Stull fired his tests at about cone 11 with fixed fluxes, so at other cones, with boron or with other fluxes the regions move. These are cautions and guides from published figures, not a test and not a guarantee of food safety.	Checks a glaze recipe for what is past a recommended limit for its firing (too much boron or alkali, too little alumina, too little or too much clay, rising expansion...) and says what the fired glaze will likely do, as the Glazecalc app does. A cone is checked in the band the recipe page gives it (low cone 06-02, mid 1-7, high 8-11); from cone 12 up (band 'top') no published limits reach, so the band's limits are not checked and limitsNote says so. With a firing, coneFit says whether the chemistry looks like that firing's, by Katz's boron rule and Hesselberth & Roy's silica and alumina whatever limit set is chosen: verdict 'cooler' or 'hotter' only when boron and silica or alumina agree on another band; 'fits' (nothing points away, not a pass); 'skipped' where the published figures do not reach (lead, lithium, much soda and potash or zinc, raku, cones 01 to 3, cooler than cone 06 or hotter than cone 10...). Cone 6 against cone 10 is told apart only roughly (strength 'soft'). stull says where the recipe sits on Stull's chart, as analyze_recipe gives it; Stull fired his tests at about cone 11 with fixed fluxes, so at other cones, with boron or with other fluxes the regions move. These are cautions and guides from published figures, not a test and not a guarantee of food safety.	No	Yes	Yes	No
`compare_recipes`Compares two glaze recipes side by side: for each, its recipe in percent, key unity formula figures, flux ratio (R2O against RO), silica to alumina, calculated expansion, place on Stull's chart (stull), the names of the limit cautions it has and, with a firing, whether its chemistry fits that firing (coneFit verdict); then what changes from A to B oxide by oxide (differences), which materials are in A only, in B only, or in both, with their percents, and a summary of the differences that matter (flux ratio, silica to alumina, silica, alumina and boron, expansion with fitFlag when the two differ by 0.3 x10^-6 per °C or more, so they may fit the same clay differently, Stull regions, the cautions only one side has, and coneFit). Give each recipe as lines (a, b) or, signed in to Glazecalc, one of your own saved recipes by its id from list_recipes (aRecipeId, bRecipeId): one or the other for each side. It is the same comparison blend_recipes makes with two recipes and two steps, under a name that is easy to find. Give base materials only, no colorants. This is a calculation from published figures, not a test result: fire both, and the tiles decide.	Compares two glaze recipes side by side: for each, its recipe in percent, key unity formula figures, flux ratio (R2O against RO), silica to alumina, calculated expansion, place on Stull's chart (stull), the names of the limit cautions it has and, with a firing, whether its chemistry fits that firing (coneFit verdict); then what changes from A to B oxide by oxide (differences), which materials are in A only, in B only, or in both, with their percents, and a summary of the differences that matter (flux ratio, silica to alumina, silica, alumina and boron, expansion with fitFlag when the two differ by 0.3 x10^-6 per °C or more, so they may fit the same clay differently, Stull regions, the cautions only one side has, and coneFit). Give each recipe as lines (a, b) or, signed in to Glazecalc, one of your own saved recipes by its id from list_recipes (aRecipeId, bRecipeId): one or the other for each side. It is the same comparison blend_recipes makes with two recipes and two steps, under a name that is easy to find. Give base materials only, no colorants. This is a calculation from published figures, not a test result: fire both, and the tiles decide.	No	Yes	Yes	No
`convert_cone_temperature`Converts between a pyrometric cone and its temperature, and between °C and °F. Orton cones run 022 to 42: Glazecalc's figure, from 022 to 15, is Orton's older chart for large cones at 150 °C an hour, and Orton's current figures (self-supporting cones at 15, 60 and 150 °C an hour, large cones at 60 and 150, cone 022 to 14) come beside it; Orton publishes no figure above cone 14, so cones from 16 up have none. SK cones (JIS R 8101, SK 022 to SK 20) by the standard's nominal figures. Give a cone, or a temperature to find the nearest cones.	Converts between a pyrometric cone and its temperature, and between °C and °F. Orton cones run 022 to 42: Glazecalc's figure, from 022 to 15, is Orton's older chart for large cones at 150 °C an hour, and Orton's current figures (self-supporting cones at 15, 60 and 150 °C an hour, large cones at 60 and 150, cone 022 to 14) come beside it; Orton publishes no figure above cone 14, so cones from 16 up have none. SK cones (JIS R 8101, SK 022 to SK 20) by the standard's nominal figures. Give a cone, or a temperature to find the nearest cones.	No	Yes	Yes	No
`create_firing_log`Saves a new firing log in your Glazecalc account (the Firing page): its title, the day, the kiln, the columns kept (time, temperature, cone, atmosphere, comments...) and a row for each reading, as the person dictated them. Add later readings with add_firing_rows. Save only what the person said and agreed to; never fill in an amount, temperature or analysis they did not give. Needs an access token that can read and change your records.	Saves a new firing log in your Glazecalc account (the Firing page): its title, the day, the kiln, the columns kept (time, temperature, cone, atmosphere, comments...) and a row for each reading, as the person dictated them. Add later readings with add_firing_rows. Save only what the person said and agreed to; never fill in an amount, temperature or analysis they did not give. Needs an access token that can read and change your records.	No	No	No	No
`create_recipe`Saves a new glaze recipe in your Glazecalc account, from its base materials and amounts (the library's names, or your own materials'), with optional colorants, notes, firing band and food-surface mark. Glazecalc works out its unity formula, as the recipe page does, and answers with it. Save only a recipe the person asked to save. Needs an access token that can read and change your records.	Saves a new glaze recipe in your Glazecalc account, from its base materials and amounts (the library's names, or your own materials'), with optional colorants, notes, firing band and food-surface mark. Glazecalc works out its unity formula, as the recipe page does, and answers with it. Save only a recipe the person asked to save. Needs an access token that can read and change your records.	No	No	No	No
`get_firing`One firing log from your account: its columns (time, temperature, cone...) and rows, and its notes.	One firing log from your account: its columns (time, temperature, cone...) and rows, and its notes.	No	Yes	Yes	No
`get_material`One material from Glazecalc's library: its oxides, loss on ignition, whether it is discontinued and what replaces it, where it is sold, hazards and the data sheet it comes from.	One material from Glazecalc's library: its oxides, loss on ignition, whether it is discontinued and what replaces it, where it is sold, hazards and the data sheet it comes from.	No	Yes	Yes	No
`get_my_settings`Your Glazecalc settings that matter when talking about glazes: region, temperature scale, cones, language, weight unit, whether lead may be suggested, the limit set recipes are checked against, the currency your prices are in (never the prices), and whether changes made by assistants wait for your approval on the website (confirmChanges: off, removals or all; it can be changed only there).	Your Glazecalc settings that matter when talking about glazes: region, temperature scale, cones, language, weight unit, whether lead may be suggested, the limit set recipes are checked against, the currency your prices are in (never the prices), and whether changes made by assistants wait for your approval on the website (confirmChanges: off, removals or all; it can be changed only there).	No	Yes	Yes	No
`get_recipe`One recipe from your account: its materials and amounts, colorants, notes, its stated firing (firedAt: the cone scale, the low and optional high cone of the claimed range, the cones the potter has test-fired, left out when none is ticked, because a stated cone from a book is not a tested one; the atmospheres and processes, and for a temperature the rate and hold; each cone exactly as the potter gave it), whether it is for a food surface, the firing logs it went through with a result note each and, where known, the cone and atmosphere each was fired at, the potter’s summary of how it came out at each cone and atmosphere (coneResults; one outside the stated firing is kept), the firing band and target specific gravity saved with it, and its unity formula worked out afresh. It is checked against the limit set chosen in your settings: for the firing given here, or else the band chosen on the recipe, or else the bands its stated firing falls in (a range across two bands is checked at each). A firing from cone 12 up is band 'top', where no limit set has figures: its limits are not checked, and limitsNote says so. coneFit says, for the same firing, whether the chemistry looks like that firing's, as the recipe page's limits panel does: by Katz's boron rule and Hesselberth & Roy's silica and alumina whatever limit set is chosen, a note (verdict 'cooler' or 'hotter') only when boron and silica or alumina agree on another band, 'closer' when a range across bands looks nearer one end, 'fits' when nothing points away (not a pass), 'skipped' where the published figures do not reach (among them firings cooler than cone 06 or hotter than cone 10). Cone 6 against cone 10 is told apart only roughly (strength 'soft'). A guide, not a test.	One recipe from your account: its materials and amounts, colorants, notes, its stated firing (firedAt: the cone scale, the low and optional high cone of the claimed range, the cones the potter has test-fired, left out when none is ticked, because a stated cone from a book is not a tested one; the atmospheres and processes, and for a temperature the rate and hold; each cone exactly as the potter gave it), whether it is for a food surface, the firing logs it went through with a result note each and, where known, the cone and atmosphere each was fired at, the potter’s summary of how it came out at each cone and atmosphere (coneResults; one outside the stated firing is kept), the firing band and target specific gravity saved with it, and its unity formula worked out afresh. It is checked against the limit set chosen in your settings: for the firing given here, or else the band chosen on the recipe, or else the bands its stated firing falls in (a range across two bands is checked at each). A firing from cone 12 up is band 'top', where no limit set has figures: its limits are not checked, and limitsNote says so. coneFit says, for the same firing, whether the chemistry looks like that firing's, as the recipe page's limits panel does: by Katz's boron rule and Hesselberth & Roy's silica and alumina whatever limit set is chosen, a note (verdict 'cooler' or 'hotter') only when boron and silica or alumina agree on another band, 'closer' when a range across bands looks nearer one end, 'fits' when nothing points away (not a pass), 'skipped' where the published figures do not reach (among them firings cooler than cone 06 or hotter than cone 10). Cone 6 against cone 10 is told apart only roughly (strength 'soft'). A guide, not a test.	No	Yes	Yes	No
`get_shelf`The materials you marked as on hand in Glazecalc (the shelf that Match with what I have uses).	The materials you marked as on hand in Glazecalc (the shelf that Match with what I have uses).	No	Yes	Yes	No
`link_firing`Links one of your recipes to a firing log it went through, as the recipe page does, and sets what came of it there: the result in the person's words (at most 500 characters), and the cone and atmosphere when they differ from the log. Linked already, it changes only what is given. A recipe links to at most 100 logs. Taking a link off is done on the website. Save only what the person said and agreed to; never fill in an amount, temperature or analysis they did not give. Needs an access token that can read and change your records.	Links one of your recipes to a firing log it went through, as the recipe page does, and sets what came of it there: the result in the person's words (at most 500 characters), and the cone and atmosphere when they differ from the log. Linked already, it changes only what is given. A recipe links to at most 100 logs. Taking a link off is done on the website. Save only what the person said and agreed to; never fill in an amount, temperature or analysis they did not give. Needs an access token that can read and change your records.	Yes	No	No	No
`list_firings`Lists the firing logs saved in your Glazecalc account, newest first.	Lists the firing logs saved in your Glazecalc account, newest first.	No	Yes	Yes	No
`list_my_materials`Lists the materials you have saved in your own Glazecalc account (not the shared library), with their oxides.	Lists the materials you have saved in your own Glazecalc account (not the shared library), with their oxides.	No	Yes	Yes	No
`list_notes`The notes in your Glazecalc notebook, newest first, optionally only those about one record (a recipe, material or firing log id).	The notes in your Glazecalc notebook, newest first, optionally only those about one record (a recipe, material or firing log id).	No	Yes	Yes	No
`list_recipes`Lists the glaze recipes saved in your Glazecalc account, newest first, optionally only those whose title or a material matches a search, or whose stated firing includes a cone or names an atmosphere or process ("which of my glazes fire at cone 10 reduction?"). Each lists its stated firing; a recipe with none has not stated one.	Lists the glaze recipes saved in your Glazecalc account, newest first, optionally only those whose title or a material matches a search, or whose stated firing includes a cone or names an atmosphere or process ("which of my glazes fire at cone 10 reduction?"). Each lists its stated firing; a recipe with none has not stated one.	No	Yes	Yes	No
`match_from_materials`Remakes a glaze recipe from only the materials listed in "have", keeping its unity formula as near as they allow, as Match with what I have does in the Glazecalc app. report.closeness says how near the new unity formula comes to the old, oxide by oxide: close (within 0.02, or 5% of a large amount such as silica's), off, or far (more than three times that), with a verdict (close, fair or poor) and a summary. report.miss and report.best are the solver's own scores, for comparing runs. Raw clay is held to 20% of the batch where that costs the match little (report.capped and allowMore say more). Test any suggestion before using it.	Remakes a glaze recipe from only the materials listed in "have", keeping its unity formula as near as they allow, as Match with what I have does in the Glazecalc app. report.closeness says how near the new unity formula comes to the old, oxide by oxide: close (within 0.02, or 5% of a large amount such as silica's), off, or far (more than three times that), with a verdict (close, fair or poor) and a summary. report.miss and report.best are the solver's own scores, for comparing runs. Raw clay is held to 20% of the batch where that costs the match little (report.capped and allowMore say more). Test any suggestion before using it.	No	Yes	Yes	No
`match_with_what_i_have`Remakes one of your recipes, or a recipe you give, from only the materials on your shelf, keeping its unity formula as near as they allow (Match with what I have). report.closeness says how near the new unity formula comes to the old, oxide by oxide, as match_from_materials does. Test any suggestion before using it.	Remakes one of your recipes, or a recipe you give, from only the materials on your shelf, keeping its unity formula as near as they allow (Match with what I have). report.closeness says how near the new unity formula comes to the old, oxide by oxide, as match_from_materials does. Test any suggestion before using it.	No	Yes	Yes	No
`move_to_trash`Moves one of your recipes, materials, notebook entries or firing logs to the Trash, as removing it on the website does. It can be put back from the Trash on the website for 30 days; nothing is deleted for good. A token moves at most 100 an hour, and none while the Trash is full. Remove only what the person asked to remove. Needs an access token that can read and change your records.	Moves one of your recipes, materials, notebook entries or firing logs to the Trash, as removing it on the website does. It can be put back from the Trash on the website for 30 days; nothing is deleted for good. A token moves at most 100 an hour, and none while the Trash is full. Remove only what the person asked to remove. Needs an access token that can read and change your records.	Yes	No	Yes	No
`remove_from_shelf`Takes materials off the shelf of materials on hand, by name. The materials themselves stay. The shelf as it was is kept: undo_shelf_change puts it back. Needs an access token that can read and change your records.	Takes materials off the shelf of materials on hand, by name. The materials themselves stay. The shelf as it was is kept: undo_shelf_change puts it back. Needs an access token that can read and change your records.	Yes	No	No	No
`search_guides`Searches Glazecalc's plain-language guides for potters (glazing from first principles, making a glaze, safe mixing, safety at home with children and pets, firing a kiln, and a companion to John Britt's free glaze course, in English only) in the language asked for, or in English where that language has no match. Returns each matching section's title, anchor, a short excerpt, its address on the website and its resource URI, which resources/read returns in full. Use it for glaze defects, safety, firing and terms, and cite the address. Link John Britt's videos by title only; never retell, summarise or quote them.	Searches Glazecalc's plain-language guides for potters (glazing from first principles, making a glaze, safe mixing, safety at home with children and pets, firing a kiln, and a companion to John Britt's free glaze course, in English only) in the language asked for, or in English where that language has no match. Returns each matching section's title, anchor, a short excerpt, its address on the website and its resource URI, which resources/read returns in full. Use it for glaze defects, safety, firing and terms, and cite the address. Link John Britt's videos by title only; never retell, summarise or quote them.	No	Yes	Yes	No
`search_materials`Finds ceramic raw materials (feldspars, clays, frits, fluxes) and, if asked, colorants in Glazecalc's library by name, alias or maker. Use it to find the exact name the other tools take.	Finds ceramic raw materials (feldspars, clays, frits, fluxes) and, if asked, colorants in Glazecalc's library by name, alias or maker. Use it to find the exact name the other tools take.	No	Yes	Yes	No
`solve_target`Makes a glaze recipe, in percent, from the materials given whose unity formula comes as near a target as they allow (Solve for a target in the Glazecalc app). The target is a unity formula (moles; the fluxes are scaled to add up to 1) or an oxide analysis (percent by weight of the fired glaze), with potash and soda apart. Give the materials by their library names, or onHand for the materials on the person’s shelf (with a token or connected app that may read it). closeness says how near each oxide comes: close (within 0.02, or 5% of a large amount such as silica’s), off, or far (more than three times that), with a verdict (close, fair or poor) and a summary; unreachable names the target’s oxides nothing given supplies. Raw clay is held to 20% of the batch where that costs the match little (capped and allowMore say more). Test any recipe before using it.	Makes a glaze recipe, in percent, from the materials given whose unity formula comes as near a target as they allow (Solve for a target in the Glazecalc app). The target is a unity formula (moles; the fluxes are scaled to add up to 1) or an oxide analysis (percent by weight of the fired glaze), with potash and soda apart. Give the materials by their library names, or onHand for the materials on the person’s shelf (with a token or connected app that may read it). closeness says how near each oxide comes: close (within 0.02, or 5% of a large amount such as silica’s), off, or far (more than three times that), with a verdict (close, fair or poor) and a summary; unreachable names the target’s oxides nothing given supplies. Raw clay is held to 20% of the batch where that costs the match little (capped and allowMore say more). Test any recipe before using it.	No	Yes	Yes	No
`specific_gravity_water`Works out a glaze slurry's specific gravity (SG) from the grams 100 mL of it weighs (or takes the SG), then, for a bucket of it and a target SG, the water to add, or to pour off after the glaze settles, as the recipe page's Specific gravity and water does. The water to add needs nothing else. The dry glaze per litre and the dry glaze and water the bucket holds (Brongniart's formula) need the dry materials' own SG: give drySg, or give the recipe's lines and it is estimated from each material (its mineral's measured density; 2.6 for commercial feldspars and clays; a frit from its oxides by Appen's glass factors), with drySgBasis saying how. Materials with no estimate (bentonite, stains, mixed borates, a potter's own) may be up to 5% of the weight and are left out; with more, there is no estimate. A drySg given wins over the estimate. Nothing is assumed otherwise. Water is 1; many dipping glazes are mixed near 1.4 to 1.5, but the right SG is the one that gives the thickness you tested.	Works out a glaze slurry's specific gravity (SG) from the grams 100 mL of it weighs (or takes the SG), then, for a bucket of it and a target SG, the water to add, or to pour off after the glaze settles, as the recipe page's Specific gravity and water does. The water to add needs nothing else. The dry glaze per litre and the dry glaze and water the bucket holds (Brongniart's formula) need the dry materials' own SG: give drySg, or give the recipe's lines and it is estimated from each material (its mineral's measured density; 2.6 for commercial feldspars and clays; a frit from its oxides by Appen's glass factors), with drySgBasis saying how. Materials with no estimate (bentonite, stains, mixed borates, a potter's own) may be up to 5% of the weight and are left out; with more, there is no estimate. A drySg given wins over the estimate. Nothing is assumed otherwise. Water is 1; many dipping glazes are mixed near 1.4 to 1.5, but the right SG is the one that gives the thickness you tested.	No	Yes	Yes	No
`suggest_substitutes`Finds the discontinued or scarce materials in a recipe and the modern ones that replace them, then suggests amounts that keep the unity formula as near as the materials allow, as the Glazecalc app does. report.closeness says how near the new unity formula comes to the old, oxide by oxide, as match_from_materials does. Test any suggestion before using it.	Finds the discontinued or scarce materials in a recipe and the modern ones that replace them, then suggests amounts that keep the unity formula as near as the materials allow, as the Glazecalc app does. report.closeness says how near the new unity formula comes to the old, oxide by oxide, as match_from_materials does. Test any suggestion before using it.	No	Yes	Yes	No
`undo_shelf_change`Puts back the shelf as it was before its last change (by the website, an access token or an assistant). One step back only: a second call finds nothing to undo until the shelf changes again. Needs an access token that can read and change your records.	Puts back the shelf as it was before its last change (by the website, an access token or an assistant). One step back only: a second call finds nothing to undo until the shelf changes again. Needs an access token that can read and change your records.	Yes	No	No	No
`update_my_material`Changes one of your own materials (an id from list_my_materials): its name, oxide analysis in weight percent, loss on ignition or notes. Only what is given changes. Recipes already saved keep their own copy of it. The material as it was is kept as an earlier version, so the person can undo the change on the website. Needs an access token that can read and change your records.	Changes one of your own materials (an id from list_my_materials): its name, oxide analysis in weight percent, loss on ignition or notes. Only what is given changes. Recipes already saved keep their own copy of it. The material as it was is kept as an earlier version, so the person can undo the change on the website. Needs an access token that can read and change your records.	Yes	No	No	No
`update_recipe`Changes one of your saved recipes (an id from list_recipes): its title, its base materials and amounts (the unity formula is worked out again), its notes, firing band or food-surface mark. Only what is given changes. The recipe as it was is kept as an earlier version, so the person can undo the change on the website. Needs an access token that can read and change your records.	Changes one of your saved recipes (an id from list_recipes): its title, its base materials and amounts (the unity formula is worked out again), its notes, firing band or food-surface mark. Only what is given changes. The recipe as it was is kept as an earlier version, so the person can undo the change on the website. Needs an access token that can read and change your records.	Yes	No	No	No
`vary_material`Shows what one material does to a glaze, by putting more and more of it into a base recipe (an ingredient blend or progression test: whiting 0 to 20, say, in 2 to 11 tiles). With mode "add" (the default) it goes on top of the base, so the recipe grows; with mode "replace" the same amount comes out of another material of the base (`instead`), so the total stays the same. Each tile has its amount of the material, its recipe in percent, its key unity formula figures (silica, alumina, boron, the fluxes), silica to alumina, calculated expansion, its place on Stull's chart (stull: region, crazed), the names of the limit cautions it has, and, with a firing, whether its chemistry fits that firing (coneFit verdict), and its flux ratio (fluxRatio: R2O alkalis against RO fluxes, in the unity formula). trend sums up what moves from the first tile to the last (oxides, silica to alumina, expansion, the R2O share of the flux ratio), which Stull regions the tiles cross, the first tile with a limit caution the first tile does not have (firstCaution) and, with a firing, the first whose coneFit verdict changes (firstConeFitChange). Give base materials only, no colorants. This is a calculation from published figures, not a test result: the tiles, fired, decide, and the cautions are guides, not a guarantee of food safety.	Shows what one material does to a glaze, by putting more and more of it into a base recipe (an ingredient blend or progression test: whiting 0 to 20, say, in 2 to 11 tiles). With mode "add" (the default) it goes on top of the base, so the recipe grows; with mode "replace" the same amount comes out of another material of the base (`instead`), so the total stays the same. Each tile has its amount of the material, its recipe in percent, its key unity formula figures (silica, alumina, boron, the fluxes), silica to alumina, calculated expansion, its place on Stull's chart (stull: region, crazed), the names of the limit cautions it has, and, with a firing, whether its chemistry fits that firing (coneFit verdict), and its flux ratio (fluxRatio: R2O alkalis against RO fluxes, in the unity formula). trend sums up what moves from the first tile to the last (oxides, silica to alumina, expansion, the R2O share of the flux ratio), which Stull regions the tiles cross, the first tile with a limit caution the first tile does not have (firstCaution) and, with a firing, the first whose coneFit verdict changes (firstConeFitChange). Give base materials only, no colorants. This is a calculation from published figures, not a test result: the tiles, fired, decide, and the cautions are guides, not a guarantee of food safety.	No	Yes	Yes	No

Details

Registry status: Active
Published: Nov 3, 2026
Updated: Nov 3, 2026
Website: https://glazecalcapp.com/assistants⁠ (opens in a new tab)
Repository: https://github.com/AaronFilson/glazecalc⁠ (opens in a new tab)
Categories (suggested): Knowledge and notesSuggested categories are assigned automatically from the registry text and may be wrong. Verified operators can correct them.
GDPR: Not declared

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