Applying Decals to Models: Complete Guide | Access Models

Decals can make or break the finish on a scale model. A good decal application should look painted on, with no silvering, no trapped air and no obvious carrier film around the markings.

The basic process is simple: prepare a smooth surface, soak the decal, slide it into position, remove excess water, use decal setting solutions where needed, then seal the finished model once everything has fully dried.

How to apply decals to scale models

These steps work for most plastic model kits, including aircraft, military vehicles, cars, motorcycles, railway models and wargaming subjects with waterslide decals.

1. Prepare a smooth gloss surface

Decals apply best over a smooth gloss finish. A matt or rough surface can trap tiny air pockets under the clear carrier film, causing the pale cloudy effect known as silvering. If the model has a matt paint finish, apply a gloss coat to the decal areas before starting.

2. Cut out one decal at a time

Cut close to the printed marking without damaging it. Work on one decal at a time so the decals do not float loose in the water or dry before you are ready to place them.

3. Soak the decal briefly

Place the decal in clean warm water until it loosens from the backing paper. Do not force it. Once the decal starts to slide with gentle pressure, it is ready to position.

4. Wet the model surface

Add a little clean water or decal setting solution to the area where the decal will sit. This gives you time to move the decal into the correct position before it starts to grip.

5. Slide the decal into place

Hold the backing paper near the model and slide the decal gently onto the surface with a soft brush. Avoid pulling hard with tweezers, as thin decals can fold or tear.

6. Align it carefully

Use a damp brush to adjust the decal. Check alignment against panel lines, doors, windows, number positions or reference photos before removing the water.

7. Remove excess water

Once the decal is in position, touch the edge with tissue or a cotton bud to draw away excess water. Roll a cotton bud lightly over the decal rather than dragging it sideways.

8. Use decal softener where needed

Decal softening solution helps decals settle over curves, rivets, panel lines and raised details. Apply it carefully and then leave the decal alone. Once softened, the decal can wrinkle temporarily and become fragile, so avoid touching it until it dries.

9. Let the decals fully dry

Give decals plenty of drying time before handling the model or applying varnish. Rushing this stage can trap moisture under the final coat.

10. Seal with a clear coat

Once the decals are dry, seal them with a suitable clear varnish. The final finish can be gloss, satin or matt depending on the subject and the look you want.

Decal setting solution vs decal softener

Decal products are often split into two jobs. A setting solution helps the decal grip the surface and reduce trapped air. A softening solution makes the decal more flexible so it can conform to raised or recessed detail.

Use setting solution first when positioning the decal. Use softener after the decal is in place, especially on curved surfaces, panel lines, rivets or complex shapes.

How to avoid silvering on decals

Silvering is usually caused by air trapped under the clear carrier film. It is most common when decals are applied over matt paint, rough paint, dust, or a surface that has not been smoothed before application.

To reduce silvering:

• Apply decals over a gloss or smooth surface.
• Use setting solution to help the decal settle.
• Remove water and air carefully from underneath the decal.
• Let the decal dry fully before sealing.
• Use a final clear coat to blend the carrier film into the finish.

How to apply decals over panel lines and rivets

Panel lines, rivets and raised details need patience. Position the decal first, remove excess water, then apply a decal softening solution. As the decal softens, it should settle into the detail. Do not press too hard while the decal is soft.

For deeper panel lines, a second light application of softener may help after the first has dried. Work gradually rather than flooding the area.

Common decal mistakes

• Applying decals to matt paint: this increases the risk of silvering.
• Soaking decals too long: this can remove adhesive and make positioning harder.
• Touching softened decals: decals become very fragile after softener is applied.
• Using too much pressure: cotton buds should roll gently, not scrub.
• Sealing too soon: trapped moisture can spoil the finish.
• Trying to place too many decals at once: work methodically, one marking at a time.

Useful decal products and modelling supplies

Different modellers prefer different decal systems, but the useful categories are the same: decal setting solutions, decal softeners, sharp cutting tools, brushes, varnishes and clean working materials.

Frequently asked questions

How long should decals soak in water?

Soak decals only until they loosen from the backing paper. The exact time varies by decal sheet, but the decal should slide with gentle pressure before being moved onto the model.

Should decals go on gloss or matt paint?

Decals usually work best on a gloss or smooth surface. Matt paint can trap air under the carrier film and cause silvering.

What causes silvering on model decals?

Silvering is usually caused by tiny air pockets trapped under the clear decal film. A smooth gloss surface, careful water removal and decal setting solution help reduce it.

Do I need decal softener?

You do not always need decal softener on flat surfaces, but it is very useful when decals need to settle over curves, panel lines, rivets or raised details.

When should I varnish over decals?

Varnish only after the decals are fully dry. The clear coat protects the markings and helps blend the decal film into the surrounding finish.