I wanted to buy an easel for my ongoing painting practice, but I realized that I could easily make one using my camera tripod. With two 12mm diameter aluminium tubes and a few nuts and bolts at hand I designed a few parts and printed them on my 3D printer. The two tubes are spaced by two end caps clamped together with three clamps. One clamp connects to the tripod. Here you can see the square connection piece, which is the same as on the platform you would screw your camera on.
The other two clamps are used to hold your painting in place. The three clamps can be arranged as desired, depending on your preferences. Here is a view of the whole construct:
This is it mounted on the tripod:
And here we have a painting clamped in it...