For businesses · 5 min read · Updated August 2026

What makes a good car ad? Designing a circle sticker that actually works

A car ad is read in three seconds from twenty feet. The design rules for circle stickers: one name, one message, stoplight-legible type — and what to leave off.

A good car ad obeys one constraint: it gets read in about three seconds, from twenty feet, by someone thinking about something else. That's the whole design brief. A Lunar circle sticker is a small canvas on a moving (or parked) car door, and the businesses that get the most from it treat it like a stoplight billboard, not a brochure: one name, one message, type big enough to survive distance and motion. Here's what works on a circle, what fails, and how the design process runs when you start a campaign.

The three-second test

Picture the actual encounters your sticker will have: a pedestrian passing a parked car, a driver two lanes over at a red light, a neighbour walking past the same driveway every morning. None of them lean in. If the essentials — who you are and what you do — don't land in a glance, nothing else on the sticker matters. Every design decision below is that test applied: distance-first, glance-first, repetition-friendly. The good news is that repetition is the medium's superpower — the same neighbours see the same car again and again, so the sticker's job is recognition, not persuasion. Recognition is what makes a neighbour's car beat a billboard.

What belongs on a circle sticker

• Your name or logo, dominant — it should own at least a third of the circle. If people remember one thing, it's this.
• What you do, in two or three words — 'Plumbing & Heating', 'Tacos & Catering', 'Family Dental'. Skip it only if the name already says it.
• One way to reach you — a short web address or a phone number, whichever your customers actually use. One, not both crammed small.
• High contrast — dark-on-light or light-on-dark, tested against both white and dark car paint. The circle's background is part of the design; car colour is the frame you don't control.
• Fat, simple type — rounded or bold sans-serifs survive distance; thin elegant fonts and script logos dissolve at twenty feet.

What to leave off

Taglines, service lists, QR codes as the hero element, social handles, and anything in sentence form. A QR code earns a small corner spot at most — it works on parked cars at close range and adds attribution, but a circle dominated by a QR code says nothing to the 95% of viewers who see the car in motion. The hardest edit is usually the service list: a landscaper wants 'mowing, pruning, cleanup, irrigation' on there, and the honest answer is that four services at unreadable size communicate less than one word — 'Landscaping' — at readable size. The details live on your website; the sticker's job is to make them look you up.

Designing for the circle itself

The circle shape rewards different composition than a rectangle: centre-weighted layouts beat edge-to-edge text, and curved text following the rim works well for a secondary line (the phone number or web address) while leaving the middle for the name. Logos designed for wide storefront signs often need a stacked or simplified variant for the circle — which is normal, and part of what gets prepared when your campaign starts: artwork is built from your existing brand assets, sized and tested for the sticker format, as part of the plan. You approve it before anything is printed, and content rules keep every sticker in family-friendly territory — a standard that protects the drivers carrying it and, frankly, your brand too.

Colour, paint, and the real world

Your sticker will ride on cars you don't choose — white sedans, black SUVs, silver hatchbacks. Designs with a solid background colour and a defined edge handle every paint colour; designs relying on transparency gamble on the car underneath. If your brand colour is mid-tone (many blues and greens), a thin contrasting keyline around the circle keeps it from melting into similar paint. And remember the medium is outdoors year-round: the printed vinyl handles weather fine — the design just needs to stay legible under rain-darkened light and low winter sun, which high contrast solves on both counts.

Judging the result like an advertiser

Before approving artwork, do the parking-lot test: print the design at actual size, tape it to a car door, and walk twenty feet away. Read it in three seconds? Approve it. Squinting? Simplify and retest. Then let the medium do its work — the dashboard reports your verified cars, mileage, and estimated impressions, and the design's contribution shows up in the slower, compounding metrics: people mentioning they've 'seen you around', direct traffic ticking up, the name coming back familiar at quoting time. Good sticker design doesn't make the phone ring on day one. It makes you the name they already know on the day they need you — which, for a local business, is the entire game.