{"id":2002,"date":"2026-10-16T16:13:59","date_gmt":"2026-10-16T16:13:59","guid":{"rendered":"https:\/\/www.artglasssupplies.com\/blog\/how-to-make-fused-glass-coasters\/"},"modified":"2026-10-16T16:13:59","modified_gmt":"2026-10-16T16:13:59","slug":"how-to-make-fused-glass-coasters","status":"publish","type":"post","link":"https:\/\/www.artglasssupplies.com\/blog\/how-to-make-fused-glass-coasters\/","title":{"rendered":"How to Make Fused Glass Coasters: A Project Guide"},"content":{"rendered":"<p>Learning how to make fused glass coasters starts with choosing compatible glass, planning a design that fits your kiln, and firing the piece according to the glass and kiln manufacturers\u2019 guidance. A simple coaster is a useful first project because it lets you practice arranging layers and observing how glass changes in a controlled, manageable format.<\/p>\n<p data-mega-cta=\"primary\"><a href=\"https:\/\/www.artglasssupplies.com\/coe96-transparent-3mm\"><strong>Choose compatible COE96 sheet glass for your project<\/strong><\/a><\/p>\n<h2>How to make fused glass coasters: what do you need?<\/h2>\n<p>Gather the materials before you start cutting. The exact setup depends on your kiln, glass system, design, and firing plan, so use the product and equipment instructions as the authority for your particular materials.<\/p>\n<ul>\n<li><strong>Fusible glass:<\/strong> Use glass made to work together in the same system. Select a base and any decorative pieces with matching compatibility information.<\/li>\n<li><strong>Cutting and breaking tools:<\/strong> A glass cutter, running pliers, and grozing pliers help you shape pieces and refine edges. Use tools suited to the glass and your experience.<\/li>\n<li><strong>Kiln and shelf:<\/strong> Confirm that the kiln has enough usable shelf area for the coaster and that the shelf is prepared with an appropriate kiln wash or shelf separator.<\/li>\n<li><strong>Design materials:<\/strong> Paper, a ruler, a marker suitable for glass, and a template help keep each coaster within the intended dimensions.<\/li>\n<li><strong>Personal protective equipment:<\/strong> Wear eye protection and closed shoes. Handle sharp edges carefully, keep food and drink away from the work area, and collect glass fragments safely.<\/li>\n<\/ul>\n<p>Start with a straightforward square or rectangle rather than a complex outline. A simple silhouette makes it easier to compare the un-fired arrangement with the finished piece and identify where a process adjustment may be needed.<\/p>\n<h2>How does COE affect a coaster?<\/h2>\n<p>COE means coefficient of expansion. It describes how much a material expands or contracts as its temperature changes. For fused glass, compatibility is not determined by the COE number alone: glass compositions also differ in viscosity and softening behavior. During heating and cooling, incompatible pieces may respond differently and place stress on one another. That stress can cause cracking immediately or later.<\/p>\n<p>Use glass identified as compatible within the same system, and do not assume that two pieces can be fused together because they look similar or have similar colors. Check the supplier\u2019s compatibility information for sheet glass, frit, stringers, and other inclusions. Do not mix COE90 and COE96 pieces in one fused project unless the products are specifically identified as compatible by their manufacturer.<\/p>\n<p>For this coaster guide, a COE96 project is one practical example. Keep the base and decorative glass within that compatible system. You can explore <a href=\"https:\/\/www.artglasssupplies.com\/coe96-frit\">COE96 frit choices<\/a> for small decorative details, but verify the product\u2019s system before adding it to a build. Our <a href=\"https:\/\/www.artglasssupplies.com\/coe96-dots\">COE96 glass dots<\/a> are another option when a design calls for repeated round accents.<\/p>\n<p>Compatibility also relates to how the glass softens and flows. A small accent can behave differently from a broad sheet, and thickness affects how a piece responds to heat. Use the glass maker\u2019s recommendations for firing rather than relying on a schedule copied from a different glass system or kiln.<\/p>\n<h2>How should you plan the size and design?<\/h2>\n<p>First measure the usable kiln shelf, not just the outside of the kiln. Leave enough room around the piece for the arrangement to sit flat and for any spacing recommended by the kiln or glass instructions. Check the coaster\u2019s intended finished size against the size of your base glass. If you plan to cut a few coasters from one sheet, account for the width of each cut and any material lost when trimming edges.<\/p>\n<p>Make a paper template for each coaster. Then sketch the placement of the base and decorative pieces. Keep the design low and even if you want a relatively smooth surface. Stacked accents, thick clusters, or pieces placed close to the edge can produce a different surface and outline than a flat, restrained arrangement.<\/p>\n<p>Plan for the possibility that the finished piece may not keep every sharp corner or exact dimension from the cut glass. Heat changes the shape of glass. The amount of movement depends on the firing process, the glass, the arrangement, and the kiln. A small test tile made from the same system and a similar arrangement can help you learn how your materials behave before you make a set.<\/p>\n<table>\n<thead>\n<tr>\n<th>Design choice<\/th>\n<th>What it suits<\/th>\n<th>What to consider<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>One flat base with a few accents<\/td>\n<td>A first coaster or a simple graphic pattern<\/td>\n<td>Keep accents compatible and distribute them deliberately.<\/td>\n<\/tr>\n<tr>\n<td>Frit details on a base<\/td>\n<td>Dots, small areas of color, or a scattered pattern<\/td>\n<td>Use a modest amount at first; loose pieces can shift during handling.<\/td>\n<\/tr>\n<tr>\n<td>Several stacked layers<\/td>\n<td>A more dimensional look<\/td>\n<td>Added thickness and uneven layers can change how the piece fuses.<\/td>\n<\/tr>\n<tr>\n<td>Several coasters in one firing<\/td>\n<td>A coordinated set<\/td>\n<td>Arrange them with the spacing and shelf capacity your kiln and materials require.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>For a set, decide whether the coasters should match exactly or share a palette with different patterns. Repeating the same base dimensions makes comparison easier, while small changes in accent placement give each piece its own character. Draw each arrangement on a separate template and label it before you cut. This prevents a common mix-up: preparing a group of bases, then forgetting which design was meant for each one.<\/p>\n<p>Also think about how the coaster will sit on a table. A compact motif in the center leaves a clear border, while accents near the edge can affect the outline as the glass softens. If you are uncertain how far an arrangement may move, keep decoration away from the perimeter on your first test. Record the dimensions you cut and the finished dimensions after cooling. That comparison gives you a practical starting point for future designs without assuming every kiln or glass behaves identically.<\/p>\n<h2>How do you cut and prepare the glass?<\/h2>\n<p>Clean the work surface and prepare your tools. Mark the glass using the template, then score it with a controlled, continuous motion appropriate to your cutter. Use running pliers or another suitable tool to separate the score. Avoid repeatedly scoring the same line. If a cut does not separate as expected, stop and reassess rather than forcing the glass toward your hands.<\/p>\n<p>Handle every cut edge as sharp. Remove loose shards from the work area as you go, and dispose of them in a container that will not be punctured. If your design needs a more refined edge, follow the instructions for your chosen grinding or finishing equipment. Clean the glass after cutting or grinding so that dust and loose particles do not remain between layers.<\/p>\n<p>Cut the base pieces to a consistent size if you are making a set. Sort and label the decorative pieces by system before assembly. This is especially useful when a studio has glass from more than one COE system on the same worktable. A clear separation step prevents an accidental mix-up.<\/p>\n<p>Before moving on, compare every cut piece with the template. Set aside fragments that are chipped, unexpectedly narrow, or too different from the intended shape. Do not try to hide a defect under another layer without considering how that extra thickness changes the stack. Wipe away fingerprints and inspect the pieces under good light. A deliberate pause here helps you catch problems while the parts are still easy to rearrange, rather than discovering them after the kiln cycle.<\/p>\n<h2>How do you assemble the coaster?<\/h2>\n<p>Prepare the kiln shelf with the separator recommended for your kiln and glass process. Let any applied coating dry as directed. Set the base glass flat on the prepared shelf. Arrange the accents on the base, then check the design from above and from the side. Look for a piece that is tilted, overhanging, or sitting on an unintended fragment.<\/p>\n<p>For a first firing, keep the assembly simple and even. If you use frit, distribute it carefully and avoid brushing it off the shelf while moving the work. Do not add glue or other materials unless they are intended for kiln use and their instructions permit the application. Place the project where the kiln maker recommends, with adequate clearance from the kiln elements and walls.<\/p>\n<p>Before firing, take a quick record of the arrangement. A photograph or sketch gives you a useful comparison after the firing. If you make several coasters, label each design in your notes and keep a record of the glass system, thickness, kiln, and schedule used.<\/p>\n<p>A short pre-fire checklist can make the process more repeatable:<\/p>\n<ol>\n<li>Confirm the labels and compatibility information for the base and every accent.<\/li>\n<li>Check that the shelf surface is prepared and dry according to the separator directions.<\/li>\n<li>Look for dust, loose fragments, or decorative pieces that extend beyond the base.<\/li>\n<li>Verify that the project is positioned with the clearance required by the kiln instructions.<\/li>\n<li>Write down the planned firing program and the details you will want to compare later.<\/li>\n<\/ol>\n<p>This check is especially useful when making several pieces at once. If one arrangement has a different thickness or shape, note that separately instead of assuming every coaster is an identical firing test. Clear notes can help you understand a result without guessing which material or layout was used.<\/p>\n<h2>How do you choose a firing schedule?<\/h2>\n<p>There is no single firing schedule that is right for every coaster. The appropriate program depends on the glass, combined thickness, kiln type and controller, shelf placement, and the finish you want. Follow the glass manufacturer\u2019s firing guidance and your kiln manual. If the two sets of instructions leave a question about your setup, seek guidance from the manufacturer rather than guessing.<\/p>\n<p>A kiln program generally controls how quickly temperature rises, how long the kiln holds at selected temperatures, and how it cools. These stages matter because glass changes viscosity as it heats. It softens and begins to move as it reaches its working range; the rate of that movement depends on temperature and time. Cooling also matters. Glass needs an appropriate controlled cool through the temperature ranges where internal stress can develop. A fast or unsuitable cool can leave stress in the piece even if it looks intact when removed.<\/p>\n<p>Do not copy a firing schedule from a project that uses a different glass system, thickness, or kiln and assume it will produce the same result. Do not open a hot kiln to inspect the work. Let the kiln complete its prescribed cycle and cool to the temperature allowed by the equipment instructions before handling the piece.<\/p>\n<p>Fusing and slumping are related but distinct operations. Fusing joins glass layers; slumping shapes a piece over or into a mold. If you want a curved coaster, that may call for a separate shaping step and a suitable mold, rather than simply changing the first fuse schedule. Consult the glass and kiln guidance for both stages. For a basic overview of how glass classes may combine cutting, fusing, and slumping, see the <a href=\"https:\/\/www.savannahga.gov\/3813\/Classes-Workshops\" rel=\"nofollow\" target=\"_blank\">City of Savannah\u2019s glass arts workshop description<\/a>.<\/p>\n<p>Keep a firing log rather than relying on memory. Record the glass type and system, the number of layers, approximate combined thickness, decoration, shelf location, controller program, and the outcome after cooling. Note whether the surface and edges match your intention, and whether the piece sits level. If you change a variable on the next test, such as accent density or the firing program, make that change explicit in the log. A clear record helps you compare like with like and ask a manufacturer a more precise question if the result is unexpected.<\/p>\n<p>When a first coaster does not look as planned, resist the urge to change several things at once. A test made with a known compatible glass system and a simple layout is easier to diagnose than a complex piece with many variables. Review whether the glass was clean, whether the layers were even, and whether the schedule followed the product and kiln instructions. Treat the next attempt as a controlled test, not as proof that every piece from that glass system will behave the same way.<\/p>\n<h2>How do you inspect and finish a fused coaster?<\/h2>\n<p>Wait until the kiln has cooled enough for safe unloading under the equipment instructions. Inspect the piece in good light. Look for cracks, sharp edges, loose material, uneven surfaces, or an outline that differs from the design. Do not use a damaged piece as a functional coaster.<\/p>\n<p>If the edge needs refinement, use an appropriate glass-working method and protective equipment. Keep the piece stable while finishing it, and clean away any glass residue afterward. Do not assume that a rough edge can be made safe by adding an untested coating or adhesive. If you plan to add feet or another backing, select materials intended for that use and follow their application instructions.<\/p>\n<p>Before making a full set, test one coaster through the complete process. Check that it sits level on the table and that the finished surface works for your intended use. Fused glass can have a textured or uneven top, depending on the design and firing. Treat a decorative surface accordingly, and avoid presenting a handmade piece as suitable for uses or temperatures that have not been tested.<\/p>\n<p>For a practical check, place the cooled coaster on a clean, level surface and see whether it rocks. View it from the side as well as from above: a piece can appear attractive on a workbench but still have a raised corner or an uneven underside. If the design includes prominent raised accents, test how a cup or glass rests on it without assuming that every vessel will sit securely. Keep the test gentle and use an empty vessel first. If it does not sit steadily, treat the piece as decorative rather than trying an untested repair.<\/p>\n<p>Think about care before you give or use a finished piece. Follow the glass and any added component instructions, and do not make claims about dishwasher safety, food contact, or heat resistance unless those properties have been established for the finished design. A simple care note can explain that the piece is handmade and should be handled carefully. This is particularly useful when surface texture, attached feet, or decorative layers make the coaster different from a plain, flat piece.<\/p>\n<h2>What common coaster-making problems can you prevent?<\/h2>\n<ul>\n<li><strong>Mixing incompatible glass:<\/strong> Sort by system and confirm product compatibility before assembly. Similar appearance is not evidence that two glasses will fuse safely.<\/li>\n<li><strong>Using an untested schedule:<\/strong> Base the firing plan on the glass and kiln instructions. Record the schedule and make a small test if you are changing a material or setup.<\/li>\n<li><strong>Overloading the design:<\/strong> Dense layers and tall accents change the project\u2019s thickness and shape. Keep an initial design simple so you can interpret the result.<\/li>\n<li><strong>Leaving dust or fragments between layers:<\/strong> Clean cut glass and the work area. Inspect the arrangement before putting it in the kiln.<\/li>\n<li><strong>Ignoring the kiln shelf:<\/strong> Prepare the shelf with the recommended separator and confirm the piece sits flat before firing.<\/li>\n<li><strong>Opening the kiln too soon:<\/strong> Follow the cooling instructions and wait until it is safe to unload. A hot piece can be difficult to handle and may still be vulnerable to thermal stress.<\/li>\n<\/ul>\n<p>If you want to explore a different compatible glass format, compare <a href=\"https:\/\/www.artglasssupplies.com\/coe90-frit-blends\">COE90 frit blends<\/a> only for a separate COE90 design, not as an addition to a COE96 coaster. Keep each project within its compatible system. For more general project ideas and technique resources, visit the <a href=\"https:\/\/www.artglasssupplies.com\/glass-art-education\">glass art education library<\/a>.<\/p>\n<p>Use a simple troubleshooting sequence if a piece cracks, warps, or comes out with an unexpected surface. First confirm that all materials were identified as compatible. Next compare the recorded thickness and arrangement with the firing guidance. Then review shelf preparation, kiln loading, and cooling instructions. If you cannot identify a likely cause, contact the glass or kiln manufacturer with your notes rather than relying on a schedule from an unrelated project. Change one factor at a time in the next small test so the outcome gives you useful information.<\/p>\n<p data-mega-cta=\"secondary\"><a href=\"https:\/\/www.artglasssupplies.com\/coe96-frit\"><strong>Browse COE96 frit for compatible coaster accents<\/strong><\/a><\/p>\n<h2>Frequently asked questions<\/h2>\n<h3>Can you make fused glass coasters with mixed COE glass?<\/h3>\n<p>Do not combine different COE systems unless the manufacturers specifically identify the products as compatible. Differences in expansion, viscosity, and softening behavior can create stress during heating and cooling. Keep each coaster within one verified compatible system.<\/p>\n<h3>Do fused glass coasters need a second firing?<\/h3>\n<p>Not necessarily. A flat design may be completed in one firing, while a design that needs shaping may require a separate slumping step. The correct process depends on the desired form and the instructions for your glass, kiln, and mold.<\/p>\n<h3>How many coasters can I fire at once?<\/h3>\n<p>That depends on the kiln\u2019s usable shelf area, the dimensions of the pieces, and any spacing or loading guidance from the kiln and glass makers. Leave the clearance they recommend, and do not crowd the shelf to fit more pieces.<\/p>\n<h3>Why did my coaster crack?<\/h3>\n<p>Possible causes include incompatible glass, an unsuitable firing or cooling schedule, uneven thickness, or other stresses in the project. Review your material labels and process notes, then ask the glass or kiln manufacturer for advice if the cause is unclear. Change one variable at a time in a small test.<\/p>\n<h2>Choose a simple first coaster and learn from the test<\/h2>\n<p>A straightforward design, verified compatible materials, and a firing plan based on the maker\u2019s instructions give you a sound starting point. <a href=\"https:\/\/www.artglasssupplies.com\/coe96-transparent-3mm\">Select COE96 sheet glass for a compatible project<\/a>, then test your arrangement and record what you learn before making a coordinated set.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Learn how to plan, assemble, fire, and finish fused glass coasters, with practical guidance on COE compatibility, kiln setup, and common mistakes.<\/p>\n","protected":false},"author":5,"featured_media":2001,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-2002","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-glass-fusing"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.artglasssupplies.com\/blog\/wp-json\/wp\/v2\/posts\/2002","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.artglasssupplies.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.artglasssupplies.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.artglasssupplies.com\/blog\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/www.artglasssupplies.com\/blog\/wp-json\/wp\/v2\/comments?post=2002"}],"version-history":[{"count":0,"href":"https:\/\/www.artglasssupplies.com\/blog\/wp-json\/wp\/v2\/posts\/2002\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.artglasssupplies.com\/blog\/wp-json\/wp\/v2\/media\/2001"}],"wp:attachment":[{"href":"https:\/\/www.artglasssupplies.com\/blog\/wp-json\/wp\/v2\/media?parent=2002"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.artglasssupplies.com\/blog\/wp-json\/wp\/v2\/categories?post=2002"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.artglasssupplies.com\/blog\/wp-json\/wp\/v2\/tags?post=2002"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}