Practical: Blank hardboard coaster can be used for sublimation ink, sublimation paper and heat press machine. You can easily DIY sublimation coasters at 355-375 degrees Fahrenheit/180-190 degrees Celsius for about 60-70 seconds. Tearing off the transparent protective film before using. Premium Material: These sublimation cork coasters are made of cork back and MDF material. The size of them is about 4x4in/10.2x10.2cm, and their thickness is about 0.16in/4mm. Product Content: You receive 40 pieces of hardboard cork coasters. Sufficient quantity meet you various DIY making needs. : MDF sublimation coasters are very suitable for sublimation, which are perfect choices for making interesting gifts. You can use your imagination to print meaningful and patterns, words, family photos, pets or beautiful natural scenery on the blank sublimation coasters, and gift them to your lovers, friends, family members and yourself. Usage: These sublimation coasters blanks are not only for DIY coasters, but can be used for placing coffee mugs, tea cups, wine glasses and various glass bottles in kitchen, living room, bedroom, , cafe, etc.