Hi everyone. I felt that I could contribute to this on a technical level. I deal with plexiglass, lexan, pvc or abs etc. with my signs. I normally use regular white acrylic for a palette. Lexan is great for a 'shatter proof' palette for all those angry artists out there
but regular acrylic will do. Lexan is much softer and will scratch easy (like a cutting board), while acrylic is a little tougher , but not as fragile as glass. I would imagine that ABS is just as good, as well as cheaper than acrylic plastic, as long as you are careful scraping the paint off. One note on Lexan: when I use a strong solvent, such as lacquer thinner, lexan becomes brittle and cracks. This may not happen as readily with milder turpentine, but it is a slow process that could occur. Lexan will also 'yellow' over time. I would stick with acrylic, which, by the way, comes in different colours as well - 1/4" thick. Acrylic and especially Lexan is not cheap, but if you take care of the palette, I would say it is your best choice. If any of you live in the Toronto area, I could probably help you out with this. Let me know if this helps.
David