TMT LED Modules for Channel letters

Individually fabricated three-dimensional letters lit from inside, typically through a translucent acrylic face.

Channel letters are named as an application for each of the modules listed below in TMT’s own product pages and datasheets. TMT’s datasheets and product pages link each module to a range of letter depths, and in some cases to stroke widths. The figures below are TMT’s published recommendations for specific products; they are not general design rules, and TMT sources do not always agree with each other.

What TMT recommends by letter size

Product	Use TMT states	Letter depth TMT states	Source
Tiny	Narrow-stroke letters (strokes as narrow as 0.5”); halo lighting on backplates (US page)	1–3 in. (global); 1.5–3 in. (US)	tmtleds.com Tiny; usa.tmtleds.com Tiny
Mini 3	Very small channel letters	Ideal 5–15 cm; channel letters and box signs 7.5–12.5 cm	tmtleds.com Mini 3; Mini 3 datasheet
Mini 2	Small and medium channel letters and capsules	2”–6”	US Mini 2 datasheet
Midi 3	Larger channel letters	2”–6” (US); 5–15 cm (global)	Midi 3 datasheet; global Midi 3 datasheet
Midi 4	Large channel letters	3”–6” (US); 7.5–20 cm (global)	US Midi 4 datasheet; global Midi 4 datasheet
Slim, Slim+	Medium and large channel letters	–	tmtleds.com Slim; tmtleds.com Slim+
TMT Midi 3 RGB	Colour-changing channel letters	–	usa.tmtleds.com Midi 3 RGB

The global Midi 4 datasheet also states that the stroke is 3x the depth of the sign (global Midi 4 datasheet). The metric and imperial depth ranges for Midi 4 do not convert exactly into each other (7.5–20 cm is roughly 3–8 in.); this may reflect separate editing of the regional files.

Module spacing

TMT supplies module chains at a standard spacing that it says can be changed on request:

Product	Standard spacing (global page)	Spacing (US sources)	Sources
Tiny	50 mm	2”	tmtleds.com Tiny; usa.tmtleds.com Tiny
Mini 2	150 mm	5.91” (page); 7” (US datasheet)	tmtleds.com Mini 2; usa.tmtleds.com Mini 2; US Mini 2 datasheet
Mini 3	150 mm	–	tmtleds.com Mini 3
Midi 3	200 mm	8”	tmtleds.com Midi 3; Midi 3 datasheet
Midi 4	250 mm (page); 305 mm (global datasheet)	12”	tmtleds.com Midi 4; global Midi 4 datasheet; US Midi 4 datasheet

Chain spacing is not the same as the layout spacing inside a letter. TMT’s Mini 2 and Midi 4 datasheets include density tables that relate letter depth to the spacing between modules and rows; these are reproduced in Module spacing and depth. TMT’s Cable Hiding feature is described as a way to shorten the gap between modules during installation (tmtleds.com Technology).

Other channel-letter notes from TMT

The US FAQ says UL registration details can be checked in UL Product iQ using the E number on the datasheet (usa.tmtleds.com FAQ).
The US site mentions a layout service for sign makers (usa.tmtleds.com Contact).
The usa.tmtleds.com Application Guide and Density Guidelines pages had no readable content on the research date (Application Guide; Density Guidelines).