Typical numbers
Sign-grade ACM is usually 3 mm with a 0.2–0.3 mm skin. Returns run 20–40 mm on monument and pan signs; anything under about 12 mm is hard to handle and hard to fix. Weight is around 3.8 kg/m² at 3 mm, 5.1 at 4 mm.
Joints and reveals
Butt joints for a continuous look; a 6 mm reveal where the design wants a shadow line; 12–15 mm open joints on ventilated rainscreen work. Whatever the detail, the panel size has to be reduced by the joint — which is what the facade breakdown does for you.
Where pan signs go wrong
Three recurring failures: returns too shallow to stiffen the face, corners notched square so the fold pulls, and groove depth guessed per operator. All three show up at install, not at the bench.
Cut list, not guesswork
Each pan gets an ID, a blank size, a groove length and a mass. On a ten-pan sign that is a shopping list for the sheet and a label for every part, so nothing gets cut twice.
Questions
How thick should an ACM pan sign be?
3 mm for most sign work up to roughly a square metre; 4 mm where the panel spans or takes wind load, or where the face has to stay flatter over a large area.
What return depth for a pan sign?
20-40 mm is typical: deep enough to stiffen the face and hide the frame, shallow enough to fold cleanly in 3 mm material.
More: ACM panel flat pattern · Rout and return, done properly · the full reference