Grimm's Large Set of Boxes - RainbowThis set of large stacking boxes in rainbow colors is an essential and versatile toy for the children: they can stack and sort the boxes by size and color, build with them, use it as doll house or car port, collect treasures etc. Plywood, non toxic water based color stain Finished with a mix of different natural oils with linseed oil as the main ingredient. This blend consists of linseed oil, olive oil, thistle oil, walnut oil and soybean oil.