An even greater stability of the structure can be given if the dimensions of the intermediate panels make the larger sizes of the corresponding row of cubes in the plan of 12 mm on each side and glue a semicircular section along the entire perimeter.
These stacks will serve as an emphasis that will not allow the rows of rows of modules-cubes to move relative to each other in either direction. This will provide the collected shelving with sufficient stability if its height does not exceed three rows. With a larger height (4-5 rows), despite the above measures, the rack must be attached to the wall, otherwise it will be unsafe to use it.
If a lined chipboard was used for the manufacture of modules, then no additional decoration of the collected rack is required. Parts from conventional chipboard and plywood must be protected from external influences and, above all, from moisture. To do this, they need to be covered with varnish or painted with colored enamels. But before applying to the parts from chipboard varnish, their surface needs to be reduced, puttled and primed.
As a primer, you can use the same varnish or enamel that were chosen for staining, but diluted by about 1/3 by the corresponding solvent. For painting small in size modules-cubes, it is very convenient to use autoemal. They have a rich palette of various colors and shades, and after drying, they form a strong protective film on the surface.