As my rooms walls are not the strongest things to put things on. I realized that what I needed to build had to be strong, but light of weight. Now I could have made the shelves out of hardboard, or small plywood. But instead I came up with the idea of using Correx Sheet, or as some people call it Sign Board, which is what they make signs from of course. You can get this in various sizes and thickness, but the size I got was only 4mm thick.
Amazon Correx Board 4mm
It's much easier too cut then the wood materials. There were some big sheets of it on Amazon so I got them. I cut one of them to the size of the backboard that I wanted. I used another to make the sides of the unit. I glued the sides on with a strong adhesive. You can use the Strong As Nails type or any glue that will stick plastics together. For the shelves I used L angle plastic strip, that you can get from hardware stores. I found it cheapest at Screwfix. Depending on how wide you want the shelves depends on how large the bottles and tins you want to store. I found that 30mm angle was enough for my needs.
It comes in long strips so you work out how many you need from the size you have chosen for the base. You then cut the L Angle to the size (width) of the shelf. The distance apart depends on the height of the materials you want to store. For example the height of a Humbrol or Revell tin will only just reach the top of the 30mm strip. Even allowing for space to get a tin out, you could get a lot of strips on your board for that. If you have made a large board for them, you can always add more strip shelves at a later date. Glue each strip to the board with a the same glue. As mine was a large piece of board I allowed two strips for the attachment of the wall mounting screws. Two on each side. Drill the holes to take the screws and then attach the strips to the board. Then drill again (when the glue dries) in the holes, all the way trough the backing Board. You can then mount them to the wall. I put a metal washer at the back to stop the pressure damaging the plastic when the screws are sent home. It goes without saying that you need a sprite level to attach both the L angle and the thing to the wall. A small one comes in handy for fixing L angles.
To stop tins falling out, I used another L angle strip this time only 10mm wide. If you want more protection you can use wider ones. Simple cut the strip to size of the angle shelf. Then before you glue to the under side of the shelf, measure your widest bottle or tin. I found that the Revell Aqua Color boxes to be quite wide, so I put two of them on each shelf and then glued the strip on. For speed I used Super Glue. But you could clamp it on, till the glue dries. You probably still need to clamp them with the Super Glue method. The edge strip doesn't need to be tight against the other. In fact it can't be if you use the Revell Aqua ones, as they won't fit the shelf! Other than that that's the job done. So here's what it all looks like:
You can see a spare angle for extra shelves on the left of the picture I also put a piece of 10mm angle on the top shelf to form a lip for storing other items on top of the unit.
This close up shows the mounting screw for attachment to the wall. You can see it on the second shelf up on the first photo too. The white cap is one that you can get that fit into the screw heads.
This image shows how different sized bottles can be stored on the same shelf.
Next photo shows the 10mm edge strip that helps prevent the tins falling out.
Lastly this image shows how narrow the shelf is compared to a commercial made paint stand.
To prove how much space can be saved, the shelf unit is back of the door, which tends to be a bit of a dead zone for putting things.
There was one item that couldn't be stored on the shelves. Acrylic Paint Pens. Th solution to this was Remote Control Holders. I found these commercially made from clear plastic.
And if you are always losing pens they can be used to store them too!