The artfelt® Tack board is recommended as it leaves no foam particles in your felted piece, as other foam may do. It is also self-healing and therefore long-lasting. If working on anything other than a crafting table, protect the table from possible puncture marks by placing several folded towels under the tacking board. This tool is essential for creating with artfelt®. It will protect your work surface from the needle tacking that you will be doing. It is made of Polypropylene, and is 1” thick.