I'm always in the search of a smaller and smaller outdoor painting setup. I been kicking around this idea for a year to integrate almost all of the major parts of a Painting setup (Easel, sketchpad, palette, water cup, paint pans) all into a Sketchbook form factor.
initial concept sketch:

high infill is recommended, I used 80% to 100% hexagon/solid infill throughout the project.
I used PLA+ but PETG is more recommended because of better temperature and uv resistance since its gonna be outside a lot.
Printed almost everything in 0.6mm nozzle/0.3mm layer height for speed, only Easel_foldcup_wall.stl is required to be printed in 0.4mm nozzle.
Print Easel_mainplatform in white plastic if ever. Saves you from painting the palette area. Sanding or enabling Ironing is highly recommended.
When gluing magnets place them in a pattern of opposite polarities. Best to glue the magnet first on the MMount_magnetmidplate.stl first, place the glued magnet behind Easel_bookboard.stl then placing the magnets will stick to their slot easily without the risk of them jumping out of the slot and slamming to the other magnets, potentially shattering it.
for the hinges put the washer, symbolized as "|" in this pattern:
bolt || Plastic |||| Plastic || locknut
Superglue ¼"-20 nut to the hexagon hole of MMount_Knurledbase.stl
The author marked this model as their own original creation.