How to 3D print a house number sign (two colors, no supports)
A 3D-printed house number sign is one of the most useful things a home printer can make: an afternoon print, a couple of dollars of filament, and a plaque that looks cast rather than printed if you get two things right — two colors and no supports.
What you need
- Any FDM 3D printer (180 mm bed or larger for a medium plate)
- Two colors of PLA, PETG or ASA filament
- A slicer: PrusaSlicer, Bambu Studio, OrcaSlicer or Cura
- Two screws with anchors suited to your wall
Steps
- Get a file generated for your address. Generic STLs from model sites have someone else's number baked in. Use a generator — PlateForge makes a print-ready STL or 3MF for your number and street, in your template and font, sized to your printer, for $5.
- Slice it face-up with no supports. Lay the plate flat on its back. Raised lettering is on top, keyhole slots are recessed into the back, so nothing overhangs. 0.2 mm layers, 3 walls, 15–20% infill. A 0.4 mm nozzle is fine; 0.6 mm works for large sizes.
- Add one filament change for two colors. The file has a single flat color boundary — on a standard plate at Z = 8 mm. In PrusaSlicer, Bambu Studio or OrcaSlicer, drag the layer slider to that height and click the + to insert a color change. Print the base in a dark color, swap, and finish the raised details in a light or metallic color. AMS/MMU owners open the 3MF instead: the two bodies are already assigned to slots 1 and 2.
- Choose filament for outdoors. PETG or ASA in full sun; PLA is fine under a porch. Matte PLA hides layer lines on the flat face; a metallic or silk PLA on the raised lettering reads like cast metal from the street.
- Print. Two to five hours for a typical medium plate, longer for L/XL. 50–150 g of filament. A textured PEI sheet gives the back a pleasant matte finish.
- Mount on two screws. Drive two screws into the wall at the spacing in the mounting guide, leave the heads about 3 mm proud, hang the plate over the heads and slide down to lock the keyholes. Use masonry plugs in brick, anchors in drywall, wood screws in siding.
Questions people ask
How big should a house number sign be?
Numbers should be at least 4 in (100 mm) tall to be read from the street — many municipalities require 4 in minimum. A medium PlateForge plate is roughly 175 × 90 mm; large and XL plates go bigger by splitting across two or three prints joined with hidden tabs.
Will PLA survive outside?
Under a porch or in shade, yes, for years. In direct sun PLA can soften on very hot days and fades; use PETG or ASA there.
Do I need a multi-color printer?
No. One filament change at the stated height gives a clean two-color plate on any single-nozzle printer. Multi-material systems just make it automatic.
Where do I get an STL for my own address?
PlateForge generates one for your number and street at theplateforge.com/design — 13 templates, sized to your printer, $5.