A stepped carcass holding 16 removable trays across four tiers. Each tray lifts out one-handed, so pens stay grouped by ink, nib, or project and the whole rack reads as a tidy stair of open trays with the pen tops standing clear above each rim.
Stepped carcass with all 16 trays in place, one tray pulled clear of tier 3 to show the modular concept.
Right side panel cut profile showing tier heights, depths, and how each tray nests flat on its tread.
One removable tray with material callouts, joinery, and the finger cutout that lets you grab and lift it with pens loaded.
Carcass is 16 by 10 by 11 inches with four equal 2.5 in tiers. Each tier holds four trays at 3.5 in W by 2.3 in D by 2.25 in H. Trays sit flat on each tread, no angled cleats, which keeps the build simple and gives clean clearance for pen tops above each rim.
Baltic birch plywood at 1/2 in gives the carcass strength and a clean laminated edge. Basswood at 1/4 in makes the trays light enough to lift one-handed with pens loaded. Total weight should land near 4 to 5 lb empty.
Butt joints with wood glue and a few 23ga pin nails or brad nails. No fasteners visible from the front. The stair structure self-locates inside the carcass once the back panel is on.
This is the concept. The full materials list, cut list, tools, and weekend build sequence live in the Pen Organizer Build Guide.