Tinker Lab just tried "Funnel Painting" and it's great to see the pictures! What fun! For more freedom, try wider paper (two sheets taped together), or cover the floor with an old shower curtain or tarp.
Quote from Tinker Lab:
This was inspired by an idea we found in Mary Ann Kohl’s book, Preschool Art. I know I’ve said this many times before, but Mary Ann’s books are brimming with creative and engaging projects, and each of mine are dog-eared in a million places. We used materials that we already had around the house — low threshold projects are my cup of tea! — and the set-up is really easy. The other thing I loved about this activity is the SCALE of it — I knew my child would be captivated by swinging a paint-filled funnel across a huge sheet of paper! Now that we’ve done this, the only drawback I could see was doing this indoors, as my daughter wanted to swing paint in every possible direction, turning me into a mini-general who curbed her enthusiasm more than I like to.