Vinyl lettering for trucks: cut vinyl vs decals, paint and magnets

The four options

• Cut vinyl. Letters cut out of solid-color vinyl film by a plotter. Only the letters stick to the door, so it looks close to paint. Good for names, USDOT numbers, MC and CA numbers.
• Printed decals. Ink printed onto white vinyl, then cut to shape. Use these when you need a full-color logo or a photo. The letters sit on a printed background, so you're applying a shape, not just letters.
• Paint. Hand lettering or painted graphics. The most permanent, and the hardest to change if you sell the truck or change your name.
• Magnets. Printed signs on magnetic sheet that come off in seconds. Handy for a pickup or van you also drive personally. See Are magnetic DOT signs legal? and our door magnets.

What the federal rule allows

49 CFR 390.21 says the marking may be painted on the vehicle or may be a removable device, as long as it meets the same identification and legibility requirements. Those requirements: it appears on both sides of the self-propelled CMV, the letters contrast sharply in color with the background, it's readily legible during daylight hours from 50 feet while the vehicle is stationary, and it's kept up so it stays that way.

So the rule doesn't care which method you use. It cares whether an officer can read it from 50 feet. For what that means in inches, see USDOT number size requirements.

Cast vs calendered vinyl

Vinyl film comes in two main types. Cast film is the thinner, more conformable kind. Calendered film is the more economical kind and handles flatter surfaces. The difference that matters on a truck door is the shape of the door.

Avery Dennison's own signage lineup shows it. Its 900 Super Cast and 800 Premium Cast films are rated for compound curves and rivets, while its 700 Premium calendered film is listed for corrugations and flat surfaces and its 500 Event film for flat surfaces only. Avery lists durability of up to 12 years for 900 Super Cast, up to 10 for 800, up to 8 for 700 and up to 5 for 500. The 900 data sheet gives up to 12 years for black and white and up to 10 for colors, measured in outdoor vertical exposure in Avery's Zone 1, and says expected durability is not a warranty. Heat, humidity, altitude and pollution shorten it.

Calendered film isn't junk. Avery's HP 700 calendered data sheet lists 6 years vertical exposure. But on a door with rivets or body lines, cast film is the safer pick. Ours is premium cast vinyl rated 5+ years outdoors.

What reads from 50 feet

Three things decide it: letter height, a heavy block font and contrast. Thin, script or decorative letters lose their shape at a distance even when they're tall. Pale colors on light paint fail the contrast part of the rule. See Truck lettering fonts and DOT lettering color and size rules.

When each one makes sense

• You own the truck and want it to look finished: cut vinyl.
• Your logo is multi-color or a photo: a printed decal for the logo, cut vinyl for the required text.
• The truck is your personal vehicle on weekends, or it's leased short term: magnets.
• You're keeping the truck for years and already repainting it: paint.

Our USDOT door lettering is cut vinyl, one pre-spaced sheet per door on transfer tape, and you can preview it on a photo of your truck type before you order.