Add a unique flourish to your entertaining accessories with this set of rough-edged slate coasters from Make Market. Made with a special polyester coating for use with sublimation inks, embellish these blanks with stylish designs perfect for handcrafted gifts or use in your own home. Details: Unfinished white with rough gray edges 3.74" x 3.74" (9.5cm x 9.5cm) coaster size7.25mm to 8.25mm coaster thickness 2 coasters Single side sublimation only Slate with polyester coating Sublimation Instructions:Pre-heat to 356°F (180°C) and press for 360 seconds. Do not exceed 400°F (204°C).Always reference manufacturer's instructions for recommended use, time and temperatures for each heating machine, as they could vary. Surface will be hot. Use protection when handling the finished product.