Wood durability & safety
Product pages describe how each wood behaves. This page holds the numbers behind those descriptions, with the sources they come from, so you can check them yourself.
How hard is each wood?
The Janka test measures the force, in pounds (lbf), needed to press a steel ball halfway into a board — the standard yardstick for dent and wear resistance. Density is the board's dried weight. Higher numbers mean a piece that shrugs off knocks; lower numbers mean lighter weight and easier hanging.
| Species | Form | Janka hardness | Avg. dried density | Source |
|---|---|---|---|---|
| Eastern black walnut | solid hardwood | 1,010 lbf | 38 lbs/ft³ (610 kg/m³) | Wood Database — Black Walnut |
| White oak | solid hardwood | 1,350 lbf | 47 lbs/ft³ (755 kg/m³) | Wood Database — White Oak |
| Baltic birch (birch plywood) | plywood | 1,210 lbf | 40 lbs/ft³ (640 kg/m³) | Wood Database — Silver Birch |
| Olive wood | solid hardwood | 2,710 lbf | 61.2 lbs/ft³ (980 kg/m³) | Wood Database — Olive |
- Eastern black walnut
- Hard enough to shrug off everyday handling; engraved lines stay crisp because the grain is even and the wood does not splinter at cut edges.
- White oak
- A third harder than walnut and noticeably heavier in hand; its closed pores are why it is the classic pick for pieces that see moisture.
- Baltic birch (birch plywood)
- The figures are for the European birch used as its veneers — Janka ratings apply to species, not panels. The void-free laminated core is what keeps fine laser-cut detail from crumbling at the edge.
- Olive wood
- More than twice as hard as walnut and the densest wood we cut — which is why olive pieces are turned as a single small form rather than a large board.
Will a piece warp indoors?
Wood keeps exchanging moisture with the air after it is cut, and it moves as it does so. Each piece is sealed by hand — oil or lacquer slows that exchange, which is what keeps a sign flat on a wall year-round. Solid boards move more than plywood: Baltic birch's cross-laminated veneers pull against each other, which is why the large-format pieces (game boards, closet dividers, nursery signs) are cut from it. The physics of wood-moisture movement is documented in the USDA Forest Products Laboratory's Wood Handbook (FPL-GTR-282), the standard engineering reference.
What is on the surface?
Each product page's Specifications panel names its exact finish. Across the catalog they fall into three families:
- Natural matte oil
- A penetrating oil that soaks in and cures rather than coating the surface. Products finished this way declare it food-safe and free of volatile organic compounds (VOCs) on their pages; it darkens the grain slightly and is water-resistant once cured.
- Natural satin lacquer
- A film finish used on pieces that get handled hard — game boards and event pieces. It is the most cleanable of the three: wipe with a damp cloth.
- Mineral oil and beeswax
- The traditional treatment for turned pieces, applied by hand. Food-safe and renewable — a fresh coat of household mineral oil restores the sheen.
Safety notes
Pieces with small removable parts — the name puzzles — carry a choking-hazard notice on their product pages: not intended for children under 3 without adult supervision. Wall pieces that ship with mounting hardware say so on their page; anything hung above a crib or bed should use that included hardware — anchors rated for the weight — not adhesive strips. Where a product declares a food-safe finish, that declaration appears in its Specifications panel — if a page does not say food-safe, treat the piece as decorative.