Right about four is when Ana got into this activity we call "Roll Printing" - a lovely way to create unique wrapping paper. And, now that Oggie is about that age, he got introduced to it recently.
Whereas Ana chose hearts and flower stickers, Oggie chose helicopter, car and letters for his work. And, as with Ana, after a few attempts, Oggie got comfortable enough to pick up paint by rolling over the paint plate, and roll the loaded roller pin over the paper (quite a tongue twister there!)
We used a flat plastic lid to spread the paint that will be picked up by the roller (we had used the backside of a pan with Ana.) Other than that, the project is much the same as described in that older post.
We used brown paper as well as easel/butcher paper for this. I let Oggie choose/mix the colors, just tempera paints, undiluted.