What a channel letter is, and the main types
A channel letter is a hollow, three-dimensional letter made of a face, a back and the side wall (the return) that joins them. The process changes a little with the type, so settle the type before anything else:
- Front-lit: the face is translucent acrylic and the LEDs sit inside; the most common type.
- Back-lit (halo): face and return are opaque, the light shines from the back onto the wall; the letter is mounted on standoffs.
- Front and back-lit: both effects together.
- Non-illuminated: for daytime visibility only, often stainless steel or painted aluminium.
Choosing materials
Material depends on the letter type, size, indoor or outdoor use and budget. The table is general guidance; choose thickness and alloy with your supplier's advice.
| Material | Where it is used | Watch out for |
|---|---|---|
| Aluminium | Returns and opaque faces; light, corrosion-resistant, paintable | Thin sheet dents easily in transport and installation |
| Stainless steel | Non-illuminated and halo letters; mirror or brushed finish | Harder and costlier to cut, bend and join |
| Acrylic | Translucent faces, opal or coloured | Scratches easily and expands with heat; keep the protective film on until installation |
| Composite panel | The background or carrier panel behind the letters | Not suited to returns; choose an outdoor grade |
How channel letters are made, step by step
- 1
1. Survey and measurements
Record the facade size, the surface the letters go on (concrete, glass, composite, sheet metal), where the power comes from and how the crew will reach it. Photos and the measured sketch must reach the designer unchanged.
- 2
2. Design and approval
Design at real size with letter height, depth, colour codes and lighting type. Nothing is cut until the customer approves in writing; the approved file is the source of the production files.
- 3
3. Production files and materials
Cutting files for faces, backs and, where useful, a mounting template are made from the approved design. Order missing material now; one missing acrylic colour can hold up the whole job.
- 4
4. Cutting
Faces and backs are cut on a CNC router or a laser. Laser gives acrylic a clean edge; for metal the method depends on your machines. Allow for the return and the fit tolerance in the cutting file.
- 5
5. Bending and joining the returns
The return strip is bent around the letter's outline by hand or on a letter bender and joined to the back. Sharp corners and tight inside curves take the most time. Outdoor letters commonly get drain holes at the bottom.
- 6
6. LEDs and power supply
Place LED modules for the letter depth and at the manufacturer's recommended spacing so the face lights evenly. Size the power supply with headroom over the total load, outdoor-rated where it is outside, and plan cable runs and connection points to make installation easy.
- 7
7. Paint
Returns and opaque faces are painted to the approved colour code. Packing before the paint has fully cured is one of the most common causes of surface damage.
- 8
8. Quality check
Compare the letters with the approved design: spelling, size, colour, edges and corner joints. Light the illuminated letters in the workshop; fix dark spots or dead modules here.
- 9
9. Packing
Pack faces under their film so letters cannot rub. Put the mounting template, screws, anchors and power supply in the same shipment and number the packages by letter or order.
- 10
10. Installation
Mark positions with the template, fix the letters, have a qualified electrician make the connection, then test and photograph the finished job.
Common mistakes
- Designing from a customer's photo without measuring on site
- Cutting on a verbal approval; a typo shows only once the letters are on the wall
- Not matching LED spacing to letter depth, leaving hot spots on the face
- Running the power supply at full load, or using an indoor unit outside
- Packing letters without lighting them during the check
- Sending the crew without the template, fixings or wiring details
Letter height, depth and legibility
Letter height is decided less by the width of the facade than by where the sign is read from. A shop sign read from across the street and a facade name seen from a ring road are not the same height. Many makers use a rough rule of thumb for viewing distance; the safest approach is still to take a photo from the reading point during the survey and show the design on it.
Depth affects both the look and the light. In a front-lit letter, less depth brings the LEDs closer to the face and the dots start to show; then the spacing is tightened or a wider-angle module is chosen. Thin typefaces and tight letter gaps mean parts that are hard to bend and too narrow for LEDs, so the designer and the workshop should pick the typeface together and solve very thin letters without light or with another technique.
Tracking the job across departments
Channel letters pass through several departments: CNC, workshop, electrics and paint often work in parallel or one after another, and it gets hard to see where a job is waiting. In SignFlow you define your own workflow stages and can send one order to several departments at once; each closes its own task, the order shows which one is still open, and the responsible department moves the job on. An order leaves design only with an approved file, and the installation is its own record with a date, an address and a crew, completed with a photo.