... friendly coloring book cover,back is 300gsm duplex paper,inside is 70gsm woodfree Reasonable price,perfect binding ... coloring book Material: cover,back is 300gsm duplex paper,inside is 70gsm woodfree, there are two ... sheets of 4c sticker paper middle.it is safe and non-toxic. Size ... two sheets of 4c sticker paper middle,inside page is 80 gsm woodfree paper.it is safe and non- ...