Casing

Casing is the process of wetting veg-tan leather and then letting it rest until it reaches the right moisture level for tooling, stamping, or molding, somewhere between soaking wet and fully dry. Properly cased leather feels cool and slightly darker than dry leather but should not feel wet to the touch.

The moisture temporarily softens the leather's fibers so a stamp or tool leaves a crisp, lasting impression instead of just bouncing off a stiff, dry surface. As the leather dries back out after tooling, the fibers set around the impression, which is why casing has to happen before stamping rather than after. Leather that dries out mid-project can be re-cased by wetting it again.

Getting the timing right takes some feel, since leather cased too wet takes mushy, unclear impressions, while leather that has dried out too far resists the tool and can crack under pressure. A common mistake beginners make is stamping the moment the leather looks wet rather than waiting for it to reach that slightly cooler, evenly toned in-between stage where the surface actually holds detail best.