How to Apply Decals on Scale Models the Right Way

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A well-applied decal can look like it was painted directly onto the model; a poorly applied one looks like exactly what it is - a sticker sitting on top. This guide covers how to get consistently good decal results, along with the fixes for the most common problems.

Waterslide vs. dry-transfer decals

Waterslide decals - the most common type in scale modeling - are released from their backing paper by soaking briefly in water, then slid into position on the model. Dry-transfer decals are applied by rubbing them directly from a carrier sheet onto the surface, without water, and tend to sit flatter but are less forgiving of repositioning once applied. Most kits include waterslide decals, so learning that process well covers the majority of situations you'll encounter.

Preparing the surface before applying decals

Decals adhere best to a smooth, gloss surface - applying them directly over a matte finish can trap tiny air pockets under the decal film, creating a slightly frosted or uneven look. Many modelers apply a gloss clear coat specifically as a decal-application surface, then switch to a matte or satin final clear coat afterward once decals are sealed. Skipping this step is one of the most common reasons decals look slightly "off" even when applied carefully.

The basic waterslide decal process

Cut the decal from its sheet close to the printed edge, then submerge it briefly in room-temperature water - most decals need only 10-30 seconds, and over-soaking can weaken the adhesive backing. Slide the decal off its backing paper directly onto the model's surface using a brush or applicator, then gently position it using a soft brush or cotton swab before it sets. Blot away excess water with a soft cloth or tissue, being careful not to shift the decal's position while it's still repositionable.

Setting solutions: softening decals into surface detail

A setting solution (sometimes called decal softener) applied after positioning helps the decal film relax and conform to raised panel lines, rivets, and other surface detail that would otherwise leave the decal looking like a stiff, raised film. A second application after the decal has partly dried further improves how well it settles into detail. This step is genuinely worth doing on any decal covering textured or detailed areas, which is most of them on a typical kit.

Dealing with silvering

Silvering is the frosted, slightly metallic-looking appearance that occurs when air gets trapped under a decal, most commonly from applying decals over a matte surface or not fully settling the decal onto the surface. A setting solution generally resolves minor silvering by softening the decal enough to eliminate trapped air pockets. For more stubborn cases, gently piercing the decal with a fine pin in the affected area and applying more setting solution can release trapped air and allow the decal to settle properly.

Sealing decals under a final clear coat

Once decals are fully dry and settled - typically 24 hours after application - a final clear coat protects them from scuffing, fading, and lifting during handling, and blends the slight sheen difference between decal film and painted surface into a single consistent finish. Skipping this step leaves decals more vulnerable to damage over the long term, particularly on models that will be handled or displayed without a case.

Aftermarket decal sheets: an easy way to add variety

Beyond the decals included in a kit, aftermarket decal sheets are widely available for popular subjects, offering alternate paint schemes, unit markings, or liveries not included in the original kit. These follow the same application process as kit decals and are a straightforward way to make a common kit feel more personal or historically specific.

Storing leftover decal sheets properly

Unused decals from a kit are worth keeping - they're genuinely useful for future repairs, spare markings on similar models, or small custom projects. Store decal sheets flat, away from direct sunlight (which can fade the printed color over time), and ideally in a sleeve or folder rather than loose, where they're prone to bending, creasing, or getting lost among other hobby supplies. A dedicated folder or binder for spare decal sheets is a small habit that pays off the first time you need a replacement marking years later, and it also makes it far easier to find the right sheet when a specific project calls for it.

Fixing a torn or damaged decal

A decal that tears during handling isn't necessarily unusable - carefully positioning the torn pieces back together on the model, using setting solution to help them settle and blend, can often produce a passable repair, especially once sealed under a clear coat. For a cleaner fix, a spare identical decal from an aftermarket sheet or a duplicate kit is worth checking for before attempting a repair, particularly on a highly visible part of the model.