FantaColor Junior 40

The 33mm buttons are chunky enough that my 4-year-old can grip them easily, and they click into the transparent board without any fuss. We've done three mosaics already this week.

My daughter sat with this for almost an hour, which never happens. The buttons pop into the transparent board with barely any pressure, so even her little hands manage it without help, and they stay put once they're in.

The 33 mm buttons are the perfect size for little hands to grab, and they sit snugly in the board without falling out when my daughter carries her finished mosaic around. Six colours is plenty for her to make just about anything she dreams up.