Builders of classic kits are served by ship paint masks at 1:400. The shelf currently holds deck masking for the battleship USS Missouri, cut for one specific kit release, and the section grows as further vessels are covered. The masking sheet shields the planked deck while you spray the non-slip areas, giving a sharp colour boundary without the hours of tape work the job would otherwise take.
1:400 sits on the border between the large and the collector scales, and deck masking suits it as well as it does bigger hulls; the stencil also spares you dozens of tape strips around anchor fairleads and deck fittings. Confirm that your box matches the release named on the mask. Matching kits are in 1:400 and 1:450 ship model kits, and stencils in other sizes, 1:350 and 1:700 included, are at ship paint masks.