Homemade RAINBOW Fibonacci Puzzle for kids These are made of ABS plastic like Lego Brand uses. The last photo shows the backside of the pieces. These were printed off of a 3D printer, so some discoloration may appear from the print bed. Will arrive in a clear bag. Note: Bending of the largest solid pieces could cause cracking. *Choking hazard warning: Pieces are small enough to ingest, please do not give to 3 and under, or small children who would eat them. (Altered from original design by ypsimon, Golden Ratio and Fibonacci's Sequence, thingiverse.com thing number 1186723. Sold under the creative commons share alike license.) Feel free to ask questions. I do offer returns within 30 days if you are not satisfied. This item is from a smoke free/pet free home. If you have any concerns upon arrival, please contact me before leaving feedback so that I can take care of the problem first. Thank you for reading my ad and have a great day!