2447, 3015 or 7328 white acrylic?

I am looking for some information on which acrylic to order for Lithophanes. There are 3 common white cast acrylic panels that seem to be consistent among suppliers. They have the number 2447, 3015 and 7328 (coinside with their transluscency). Anyone had any experience to know which is best for backlit lithos?

Saw both posts - here's my take.....

Corian or CAST acrylic is what you want.

Regarding translucency, Corian is not translucent at all, until you carve it down to about .13".

I'd go with the least trans., would seem to be closest to Corian.