Description states "Made of polyester". That meaning didn't 'sink in' 'til I handled it 7 tried to cut it, that it hit me INSTAN Since I spent the money, I wanted to know what I could use it for other than my original plan because that simply was not what I was expecting. When I cut it with scissors the top + bottom of sponge where I cut, were stuck together in one seam. It just stayed that way. Til the next day when I gently pulled the edges apart from each other. I soaked this thing in a bowl of water. I squeezed lighting to try to encourage absorption as this is not a product design to do heavy absorbing. I only gut a minimal piece off the sponge. But there was well ove 5/6th's remaining. After soaking..and squeezing and soaking, i lifted it from the water bowl and water dripped out of it I caught every drop and then squeezed it til the entire thing fit inside my small hand (size 5 ring finger). I poured all the water into a 1/4 measuring cup and it didn't fill it. Close enough I'll say. So that big sponge isn't absorbent. Therefore, I would call it more of a "stamp". If you want to lightly paint on your thin sheer colors for mottling, this can work. Yet, just my opinion, I'd test it on a white paper plate for color and pressure...but getting product ON the 'sponge', and off of it to get your own routine that works well. As far as the memory foam organization, here's what it says about polyester, etc.:
Polyester in Bedding (COPY/PASTED) Quotes: Properties of Polyester. Polyester does not absorb water... The most common use for polyester fibers is in clothing, but it is also one of the materials used in bedding. Outlook The utility of polyester in textiles and cushioning fibers assures it a place in mattress and pillow materials for the foreseeable future. (END OF COPY)
It's a great product. Very comfortable. Hard to work with until you know your plan of use and don't expect it to behave like a "sponge sponge'. I think the design with all the holes helps it hold some water. And it hold great potential as a stamp or applicator of colors. It cleans up easily and seems very durable. Once someone puts it on a stick or a curved wooden block, and markets that, it'll probably sell like hot cakes for applying detail!