We have had lots of requests to design an insert for our Really Useful Box trays that allow for a whole tray of paints to be stored. These are now available, we have made one to fit bottles (Vallejo & Army Painter), and another to hold pots (GW, Foundry / Coat d'arm). Both types of inert include a spacer so that the insert sits at the right height in the tray. The inserts are half width so you can either have two the same or one of each in a single tray. The inserts are available for Type 'A' Trays (European 4 & 9 Litre), Type 'B' (European 19 & 25 Litre) and Type 'D' (US 4 & 9 Litre).
Paint storage trays to fit inside Really Useful Boxes. You can store the pots / bottles upside down if you want so the pigment is at the top of the bottles.
Full details on web site:
http://wargamesbuildings.co.uk/RUB