How it's made. A vector PDF's line work is read directly (walls, doors, stairs — the text and dimension strings fall away); a photo is traced with a local-contrast threshold so glare and uneven light don't matter, and every traced plan is checked by a person before it prints. The walls are stroked to 1.6 mm and stand 1.4 mm off a 3 mm plate; the route is a 2 mm line with an arrow, the marker a raised dot, all in their own colors on one flat print — no supports. The title is set 1 mm into a band along the bottom. Two blind keyholes on the back hang it on a pair of screws. Tactile plaques supplement the code-required evacuation signage; they don't replace it.