Common materials include soft fabrics and plastics, cotton, pine and other woods, silicone trim, and paper/cardboard or MDF.
Labels vary widely: some sets are marked “Newborn and Up” or “3 Years and Up,” while many use month ranges such as 6–24 months, 9–36 months, or 12–36 months. You’ll also see tags like “18 months and up” and “2 years and up.”
Some learning sets use multi-faced blocks—examples include double-sided blocks and six-sided blocks that show both uppercase and lowercase letters. These multi-faced pieces often also include numbers, pictures, or other symbols on the remaining faces.