I have a lot of craft paint that I wanted to organize in my cabinets. I measured out 9x9 blocks with 5x5 inserts to hold paint.
The cubbies I have are approximately 9 inches x 9 inches. In XCS I created a 9x9 inch square.
I also created what will be the supports to connect the front and back. This should be as wide as the square above and as a bit shorter than the paint you want to store. I did 9x2 inches.
Create a circle big enough to encompass your paint tubes. In my example, they are approximately 1.6 inches to give some extra spaces. Then use the Grid array to multiply wide and high enough to fill the square/rectangle you made in the last step.
I reduced the space between the circles significantly, but make sure they are thick enough to hold your paint/not break easily.
Cut this file twice to create the front/back and top/bottom of the organizer. Glue the thinner rectangles along the top/bottom. Use tape to keep stable while the glue dries.