Yet another take on a wet palette -- this version is based on [one](https://www.prusaprinters.org/prints/36514-wet-palette) posted on the prusa site. It used 8 3mmx7mm neodymium magnets to hold the frame in place.
To use, put a damp paper towel or sponge in the bottom and cover with a piece of parchment paper (baking paper in Europe?) cut to size. Hold it all in place with the frame and you're good to go.