I wanted a way to easily switch out the paint in my little box. I use regular paintboxes but sometimes also (altoid) tins. The instructions I found required glueing in the pans permanently or use putty to temporarily stick them in. Putty worked, made the pans easily removable, but a bit messy / sticky. I decided only one thing would give me the flexibility and ease I wanted: MAGNETS
I did find one instructable that used magnetic tape, however, the one I found, wouldn't really stick, and it also added more padding to the pan which made them not fit so well in my regular paintbox (it wouldn't close anymore)

(besides, I like magnets)

I didn't need much to get this to work:

- empty pans
- tubes of paint
- small but strong magnets
- empty altoid tin or paintbox
- water
- knife (optional, for pre-filled pans)

Step 1: Place Magnet in Empty Pan

Place the empty pan in an altoid tin so it won't move around to much. Add magnet to centre bottom.

Step 2: Fill Pan With Paint

Try to get it into the corners as much as possible.

Use a toothpick to swirl the paint around a bit to get air-bubbles out and to get it into the corners.

Step 3: Optional: Use Pre-filled Pans

I have used this paint before, and I have a bad habit of creating wells in the centre. After I wiggled the paint out of the pan with a knife, I placed the magnet in that well and placed the paint - with a bit of water - upside down back in the pan.