Years ago, the Church made a quilt for the pastor's new baby. There were signature squares for older children and adults to sign. The borders were the little children's hand prints.
Used Jacquard or Luminere from Joann or Michael's. During Sunday School, an adult brought 1 child at a time to my station. He held the child and I held the child's hand. Dipped the hand in paint then pressed it down on the fabric. If it didn't turn out, we did another. The child and hand were immediately taken to the sink and washed thoroughly. Then the hand print was labeled with the child's name. The children were thrilled with their hand print and it was a hit with the adults and pastor/family.