I've bought many, many packs, many times and use them often for my students. Great for mixing watercolour colour paints. The pack contains 5 x trays. They are plastic trays - thin plastic and light.
Not sure if I would use them for oils or acrylic paints as they would need to be washed and cleaned often, but for watercolour paints they are absolutely perfect.
I stack up all the palettes at the end of my lessons alternating the palette, (so they don't collapse into each other) if you stack them on top of each other the paint will dry and get stuck. But if you alternate one side then the other you can stack them so that the air gets in between and the watercolour paints will dry, ready for the next session. I would recommend these only for watercolour paints. If you need something more robust and permanent best buy a heavier plastic palette
Very speedy delivery. These are quite flimsy but served the purpose for which I ordered them, they did stain but I will be able to reuse them several times