It is solid PVC, it is Veranda product I purchase at Home Depot. Here is s pic of the sticker from the backside of the 1/2" material. The 1/4" doesn’t give any detail other than 1/4" PVC. hope this helps.
You need to run it at at least 80 ipm. it cuts easy so you can be aggressive with cuts
I use the 2 flute SC bit from Inventables and Whiteside Carbide 60 or 90 v bit. I have looked and cant seem to find 1/16 and 1/32 straight flute bits. there are times i DO NOT use the v bit for fine detail.
down cut not good but works. up cut pulls the oramask off and buries pvc in the edge.