|i would be lost with out this handy little thing. it is a heavyweight piece of heat resistant plastic that is translucent. it is used as a pressing sheet for use with fusibles. it really cuts down on the mess on the bottom of your iron. i use it for attaching fusible interfacing (which always seems to be bigger than my fabric piece ) to facing pieces. instead of the fusible going directly onto your iron, it goes against the plastic. after it cools, any little blobs of fusible can be peeled off the sheet and thrown away. sometimes, when my sheet is exta icky, i have even laundered it. it comes out a little wrinkly but a quick press and its back to normal. i first started using this thing years ago when i did alot of machine applique. fabric with stitch witchery or wonder under, heat and bond peel right off once it cools down. nifty little gadget !!!