Flat Coaster Moulds: Choosing Heat-Resistant Resin

If you’re creating flat coasters in silicone moulds, heat resistance is an important factor—especially for hot drinks. Not all resins are equal in this respect, so choosing the right one will help you make durable coasters fit for daily use.

Why Resin Selection Matters for Coaster Heat Resistance

Regular crafting or casting resins may soften or mark under heat from hot mugs. For coasters that need to withstand higher temperatures, it’s essential to use a specialised heat-resistant resin. These are formulated to hold their structure and gloss even when exposed to hot drinks.

Most heat-resistant resins used for coasters require a minimum thickness to be effective. For best results, start your project by pouring a 3mm clear layer of heat-resistant resin into your mould. This creates a protective barrier that is better able to handle the demands of daily use.

Tips for Working with Heat-Resistant Resin in Silicone Moulds

Let your heat-resistant resin layer fully cure—usually up to 72 hours—before demoulding or exposing it to any heat.
If you want to add decorative touches (like glitter, inks, or dried flowers), pour your clear heat-resistant layer first, allow it to cure, and then add your coloured or embellished resin layers.
To achieve a professional, smooth finish, select a mould with a flawless interior, such as the “O” – Geode Coaster Silicone Mould.

When Is Heat-Resistant Resin Essential?

If your coasters will regularly support hot cups or mugs—such as in kitchens, offices, or dining areas—investing in heat-resistant resin makes a noticeable difference in longevity and appearance. For purely decorative coasters or those used with cold drinks, standard resin may suffice.

Related products

For reliable, everyday use, start with a suitable heat-resistant resin and a high-quality silicone mould. Learn more about crafting unique and functional pieces on our Silicone moulds for coasters hub page.