The material of a built-up letter decides how it is made, how it looks up close, how heavy it is and which finishes are possible. Most channel letters combine materials: a metal return with an acrylic face, an acrylic letter with an aluminium side band, a stainless letter on an acrylic base. This guide explains what each material brings, so you can match it to the brand, the budget and the location.
The main materials at a glance
| Material | Strengths | Typical finishes | Where you find it in our range |
|---|---|---|---|
| Stainless steel | Premium metal look, crisp edges, many self-colour finishes | RAL paint, electrostatic powder coat, chrome, brushed, gold, rose gold, bronze, copper, black | SML 2, 3, 3 EXCLUSIVE, 4, 4 EXCLUSIVE, 6 |
| Aluminium | Light, versatile, easy to paint | RAL paint, static (powder) paint, coloured side bands | SML 1, 2, 3, 5, 6 |
| Acrylic (Plexiglas) | Translucent faces, solid glowing letters, printable | Self-colour, translucent foil, digital print | Faces of all face-lit letters, SML 7, 8, 9 |
| Composite / PVC foam | Economical flat letters and backs | Paint or foil | SML 1; PVC foam backs on several profiles |
Stainless steel: the premium metal
Stainless steel is the material of choice when the letter itself has to look expensive. In our production, stainless letters are laser-cut and laser-welded, which gives clean returns and sharp corners. The metal can be painted to any RAL colour or electrostatically powder coated, but it is often left in one of its own finishes: chrome (mirror), brushed (satin), gold, rose gold, bronze, copper or black.
Stainless is the main material of SML 3 EXCLUSIVE, where it sits on a 20 mm acrylic base for an even halo, and it forms the return and trim of the face-lit SML 4 and SML 4 EXCLUSIVE. For unlit metal letters, SML 2 is available in stainless steel, including gold mirror.
A practical note: mirror and gold finishes show reflections and fingerprints, so handle and clean them with care. If a sign will stand close to the sea or in a harsh industrial atmosphere, discuss the stainless grade and finish with your supplier before ordering.
Aluminium: light and versatile
Aluminium is lighter than steel and easy to cut, form and paint, which makes it a natural choice for larger letters and painted returns. In our workshop aluminium letters are CNC-cut and argon-welded, then painted in the RAL colour you specify.
Aluminium appears in many profiles. It is one of the two metal options for non-illuminated SML 2 and halo-lit SML 3. In SML 5 ECO it forms the painted side band that is bonded to a CNC-cut acrylic face – available in 4, 6, 8 and 10 cm depths and in white, red, black, blue, mirror silver and mirror gold. SML 6 can be built in aluminium or stainless steel, with stainless generally preferred.
Acrylic (Plexiglas): light that shows
Acrylic – often called Plexiglas, after one of the best-known brands of PMMA sheet – is what makes a face-lit letter glow. Translucent acrylic diffuses the light of the LED modules behind it, and its thickness is chosen to suit the letter size. Colour comes from self-coloured sheet, from translucent foil applied to the face, or from digital print when a specific colour or an image is needed.
Acrylic can also be the whole letter:
- SML 7 is a solid acrylic block letter, 30 or 40 mm deep, with sides painted to RAL or foiled and a choice of front, side and back lighting combinations.
- SML 8 is an acrylic channel letter in classic or Italian style, usually on a PVC foam back; light can also come out through the side band.
- SML 9 uses vacuum-pressed (thermoformed) acrylic faces for domed, rounded shapes.
For special face materials, SML 6 also offers Elkamet and emboss options alongside 5, 10 and 20 mm acrylic.
Composite and PVC foam: flat letters and backs
Not every letter needs a return. For flat cut-out letters, SML 1 is produced by CNC router or laser from composite panel, PVC foam, acrylic, aluminium or stainless steel, then finished in powder coat, spray paint, foil or the material's own colour. The letters are fixed flat with double-sided tape or raised on stand-off screws.
PVC foam also plays a supporting role: it is the standard back of several channel letter profiles, including SML 2, SML 5 and SML 8, while metal backs are available where the design needs them – for example on SML 4 EXCLUSIVE or SML 8 version #2.
Indoor or outdoor?
All of these materials are used both inside and outside, but the location changes the priorities:
- Outdoors, think about rain, sun, temperature changes and cleaning access. Illuminated letters also need weather-appropriate electrical components – see our guide to LED modules, power supplies and IP ratings.
- Indoors, the letter is seen up close, so edges, joints and finishes matter more. Solid acrylic and polished stainless steel are popular for receptions and shop interiors.
Matching material to profile
| If the brief says… | Consider |
|---|---|
| Metal letter, no lighting | SML 2 (aluminium or stainless), SML 1 (flat) |
| Metal letter with a halo | SML 3 (aluminium or stainless), SML 3 EXCLUSIVE (stainless) |
| Bright face in brand colour, metal sides | SML 4, SML 4 EXCLUSIVE, SML 6 |
| Illuminated letters on a tight budget | SML 5 ECO |
| Glowing acrylic, interior or retail | SML 7, SML 8, SML 9 |
Once the material is clear, the next step is the full specification. Our guide on how to request a channel letter quote lists what to send, and every profile has a data sheet on the channel letters overview.
Frequently asked questions
Is Plexiglas the same as acrylic?
Yes. Plexiglas is a well-known brand name for acrylic (PMMA) sheet, and the word is widely used for acrylic in general.
Can stainless steel letters be painted?
Yes. Stainless steel can be painted in RAL colours or electrostatically powder coated, or left in a self-colour finish such as chrome, brushed or gold.
Which colours are available for the SML 5 ECO side band?
The painted aluminium side band of SML 5 ECO is available in white, red, black, blue, mirror silver and mirror gold, in depths of 4, 6, 8 or 10 cm.
Which material is used for halo-lit letters?
SML 3 is made in aluminium or stainless steel; SML 3 EXCLUSIVE is mostly stainless steel on a 20 mm acrylic base that spreads the light evenly.
