They are made of a sturdy paper material. Blank Jigsaw Puzzle is a fun way to create your own personalized puzzle. It is for weddings, showers, birthdays, invitations, and classroom or home activities. Decorating these puzzles is so much fun. You can decorate yours and with a friend to see if they can solve your puzzle. Make it as challenging or easy as you desire. Features -Color:White -Material:Paper -Heart Shape Size: 18.50X16.50X0.30cm/7.27X6.48X0.12in; -Round Shape Size: 16.70X16.70X0.30cm/6.56X6.56X0.12in; - This is DIY blank puzzle, made of paper materials, very suitable for DIY, craft and art projects. - Children can use crayons, markers, pencils, watercolors, glue or any creative materials to decorate puzzles with their own designs. - Suitable for boys and girls, the rounded edges are safe for children, reliable and excellent. - You and your child can use it repeatedly, and will feel something to do for long period of boring time. - Children will love to play with it and enjoy the fun of disassembling and reassembling them. Package list: 5 x round design puzzles 5 x heart shape design puzzles