Paint organiser for Schipper

This is a paint organiser for Schipper Paint by numbers paint trays. (Check https://www.malennachzahlen-schipper.com/Default.aspx?Lang=en-gb for details about their exceptional products). I found the delivered trays not so stable, so i designed this organiser. I designed also paintbrush stand, check: http://www.thingiverse.com/thing:1323283