Choosing a decal size for doors, sills, glass and spoilers

Size is the decision that most often decides whether a graphic looks considered or improvised, and it is the one buyers think about least. Two cars can wear the same design, one clearly and one awkwardly, and the only difference is how the size relates to the panel around it.

The useful principle is margin. A graphic needs clear panel around it to be read as a deliberate shape rather than as a panel that has been covered. That margin is what gives the design its edge definition, and it is the first thing lost when someone orders the largest option available.

Doors and rear quarters

A side graphic reads best when it occupies roughly half to two thirds of the door's height and stops short of both the front arch and the door shut. Running an edge into a panel gap looks accidental; running it across the arch looks like the graphic was cut off. Along the length, a graphic spanning most of the door and ending cleanly before the rear arch is a safe proportion on a 911, while a shorter, more concentrated motif suits a 718's shorter door.

Watch the shoulder line. A graphic that crosses it at a shallow angle will look like it is sliding off the car; one that follows it, or sits entirely below it, looks intentional. Our side blade kit is proportioned to taper out over the rear arch rather than stopping mid-panel, which is the detail that makes a full-length graphic work.

Sills and lower doors

Low graphics are read at a glance from a distance, so they tolerate a longer, thinner proportion than anything higher up. A sill strip should follow the line of the sill rather than the door's bottom edge, because those two lines are rarely parallel. Keep it narrow: a strip that is deep enough to reach the door's crease will compete with the body line rather than accent it.

Glass

Windscreen sun strips

A sun strip has a functional limit as well as a visual one. It should sit above the driver's forward sightline, which means a shallow band on a steeply raked screen. Measure from the driver's seat with the seat where you actually drive, mark the top of your view, and keep the strip clear of it. Then keep the lower edge straight and parallel to the screen's top edge; a wavy lower edge is the most common reason a sun strip looks wrong.

Depth should also respect the screen's curve. On a deeply curved screen, a strip that is too deep will start to follow the curve at its ends and appear to droop. A narrower strip stays visually level. Our windscreen sun strip is cut to a depth that keeps the lower edge reading straight.

Rear and side glass

Glass graphics work best as a simple shape with a clear margin, because the glass itself provides the contrast. A rear screen graphic should leave the high-level brake light and any heating element zones clear. Avoid placing a solid area directly over the wiper's rest position, where it will be abraded.

Spoilers and wing endplates

Endplates are small, visible and seen from the side, which makes them ideal for a compact motif and unforgiving of anything detailed. A shape that needs to be read at arm's length is the right scale here; a fine pinstripe or small text will disappear at three metres. If a kit places the same motif on the roof and the endplates, as our roof and endplate kit does, the endplate version is usually the smaller of the two and is scaled to the plate, not copied from the roof.

Bonnet and roof

Horizontal panels are seen from a distance and at an angle, so a graphic here needs a strong, simple shape. Twin stripes work because the gap between them provides the definition; a single wide band often reads as a block of colour. Leave a margin at the panel edges and at the bonnet's shut lines, and be careful around washer jets and vents, which are where bubbles and lifting begin.

Width, length and the gap between

Width and length do different jobs, and confusing them is why some graphics look almost right. Length governs rhythm: it decides where a design starts and ends relative to the panel's own lines, and a graphic that ends in the wrong place will look wrong even if it is the correct width. Width governs weight: a narrow graphic on a large panel looks tentative, and a wide one on a small panel looks heavy.

On twin stripes, the gap is a third dimension and usually the one that decides the result. A gap that is too narrow turns two stripes into one patch of colour; a gap that is too wide makes them read as two unrelated lines. A useful starting point is for the gap to be roughly the same width as one of the stripes, adjusted by eye once the template is on the car. Follow the panel's centre line for symmetry and measure from both edges rather than trusting one.

Multi-piece kits are scaled as a set, not piece by piece. Where a kit places graphics on the roof and the wing endplates, as our roof and endplate kit does, each element is sized to the panel it sits on rather than being a copy of the largest piece. Changing one element's size to suit a preference breaks that relationship, which is why it is better to choose a different kit than to scale part of one.

Judging size before you order

You can check a proportion without buying anything. Cut a paper template to the size of the intended graphic, tape it to the panel with low-tack tape, and step back five metres. Look at it from the front quarter and from the side. If the template looks like it is floating unattached to the panel's lines, it is the wrong size or the wrong place. If it looks like it could have been painted on, you have the proportion right.

Whatever you choose, confirm the kit is cut for your model and year with the fitment checker before ordering, because the correct size for a 992 door is not the correct size for a 996. Browse the full range at all products, and if you want to see a design on your own car first, the design visualiser will show it on a model before you commit.