The Art of Applying Decals

by Joe Czapiga

DecalsThe art of applying thin film wet decals to models is one that only gets better with practice. If at first you don’t succeed, try and try again.

Patience and persistency will allow you to produce models that look as good, if not better than the models in all your favorite magazines.

I am sure many people have many different methods of applying decals successfully. The methods I use were mostly developed by trial and error and lots of query at every hobby shop I’ve gone to.

As for the myth that you won’t be able to produce a great looking model until you have 20 years of experience, forget it. I have always loved trains, but I have only been a modeler for about three years. It has only been about one year since I decided to try custom painting and decaling.

If you have never tried to apply thin film decals before, your first experience will probably be one of impatience and frustration. These decals are very delicate and can be ruined very easily. For your first project, I recommend practicing with simple decal jobs which do not require strict alignment in order to look good.

Usually, rolling stock such as box cars (smooth sided), covered hoppers, etc. have pretty simple paint schemes. Many are only one or two colors. Stay away from thin, long, longitudinal lines on the long hood of a locomotive such as the GATX units you see on the St. Lawrence & Atlantic. Even the most experienced modeler can have difficulties with these.

Tools for the Task

Applying decals also requires some special tools. What I mean by special tools is you probably have them in your hobby tool box but might not think they would be used to apply decals. Here is a list of tools & supplies I have within arms reach when I apply decals to a model:

  1. A shallow bowl filled about 1/2 way with luke warm water.
  2. Scissors (preferably small to medium size).
  3. Hobby knife.
  4. Two small detailing paint brushes.
  5. Solvaset (decal setting fluid).
  6. Bath tissue or Kleenex (NOT paper towels).
  7. Two No.2 pencils with an eraser.
  8. Cross locking tweezers.
  9. Decals.
  10. Prototype photos (if you have any).

After you have all these items together you’re ready to apply decals.

If by now you don’t have a model to decal, it would probably be a good time to get one. Decals stick the easiest to glossy finishes. They will stick to dull finishes just as well but are much harder to work with on this type of surface.

The decals don’t slide into place as easily making it much more critical to place them almost exactly where they need to be with little or no adjustment. Because of this it may be more difficult to remove any air bubbles under the decal. First time decalers should choose something with a glossy finish. Glossy paint or clear gloss coat work equally well.

The first thing to do is to get all your tools listed above and your model and set them up on a clean flat surface with good lighting. Make sure you have plenty of room to spread out your tools so they can be easily reached if you need them quickly. Make sure you wash your hands thoroughly before you start.

Two Types of Decals

Next, choose a decal you would like to apply. At this step it is a good idea to know what type of decal you are about to apply. I am familiar of two different types; Type One is printed on a plain old sheet of decal paper, and Type Two has each individual decal printed on decal film which is then applied to the paper backing.

With Type One you must trim as close as possible to the design of the decal you are going to apply, otherwise the excess may become visible when it dries on the model. Type Two decals can be cut as close or as far away from the design as you like.

Cut Out Your Decal

Whichever type you have, cut the selected decal from the sheet and place it on the model where you would like it to be. Lining things up and visualizing what you want to do before you put the decal in the water is very important. Once you put the decal in the water, things can get difficult.

Third, you will want to wet the area where the decal will sit with some of the warm water. Use your paintbrush for this. Wetting this area will help reduce air bubbles under the decal and help you maneuver the decal into place.

Micro Set Setting SolutionWhen you become more experienced at applying decals, you may use the Solvaset to wet the area instead of water. There is an advantage and a disadvantage to using Solvaset instead of water.

Using water allows you unlimited time in adjusting and lining up your decal where you would like it, but does not eliminate air bubbles under the decal (it only helps to minimize).

Using Solvaset eliminates air bubbles almost entirely, BUT, and I stress BUT, you only have about 20 seconds (maximum) before the Solvaset softens the decal making it almost impossible to maneuver.

Soak the Decal

Now you may take your decal and place it in the water. I usually hold the decal with cross-locking tweezers as I place it in the water. Sometimes it is difficult to retrieve a decal, especially if it is small, from the bowl of water if you just toss it in. After about 15-30 seconds you should be able to move the decal around on the paper backing. If not put it back in the water for about 10 seconds more.

Once you can move it, place the decal and paper backing (do not remove the decal from the backing yet) on your index finger. Remove the cross-lock tweezers, slide the decal just a tiny bit to the opposite side of the hand your tweezers are in, and re-apply the tweezers to the backing paper ONLY. Now you have the backing paper and a decal which is free to slide in any direction you would like.

Position the model so you can place the edge of the decal on the model. Then hold that edge to the model with your paintbrush and slide the decal paper backing away. Try to keep the decal as close to the model as possible while pulling the backing paper.

Place the Decal

Once you have removed the backing paper, use your paintbrush to position the decal. Pushing on the edges of the decal is most effective. You may also use the eraser of a No.2 Pencil to move the decal around. Remember, if you used Solvaset instead of water to wet your surface, you must work fast.

Position the decal where you would like it to be. Try to push out any air bubbles under the decal by rolling the bristles of the paintbrush to the outer edge of the decal. After all of the air bubbles have been removed, very gently brush on Solvaset sparingly while not moving the position of the decal. Be sure to cover the whole decal, especially around the edges. The Solvaset usually works its way under the decal pretty good.

Allow the Decal to Dry

At this point you should put the model down and let this decal dry. If you are confident enough you may apply more decals, but remember the decal you just applied is very fragile. If you touch it before it dries you will probably ruin it.

Sometimes the Solvaset makes the decal appear as if it is wrinkling up. This is normal. The decal will set flat on the model when it dries. When the decal does wrinkle, keep an eye on it. If it appears the wrinkle is not coming out on its own you may have to get those wrinkles out.

Before you attempt to move the decal, carefully brush on some warm water (no more than a 1/2 drop or so).Carefully use your paint brush to drag the decal from the outer edges away from the center of the wrinkled area. The decal’s position on the model should not be compromised by this. You should only have to move part of the decal a distance equal to the thickness of the wrinkle.

Inspect the Decal

After the decal dries, inspect it for air bubbles that you missed the first time. If there are any, make a tiny hole in the decal with a pin and brush on some Solvaset making sure it gets in the hole and under the decal. The Solvaset will soften the decal again and make it set to the surface of the model.

Since the decal is soft and wet again you should allow it to dry. Drying times may vary; I recommend at least an hour or so. Usually I will let them dry about an hour before I apply another decal unless I know I can do it without disturbing the one I just applied.

Final Treatment

Finally, I recommend a gloss or dull coat be applied by air brush or spray can to the model after all the decals have been applied and have dried. This will help “hide” the decal edges and make your model look realistic.

After you have practiced these methods a few times and develop some of your own, you will be able to produce models of superior quality.

Your Thoughts

Do you have another method or tip for applying decals to your model railroad cars, locomotives, or scenery? Share it in the comments area below.

About Model Train Tips

I am a complete model railroading novice, and I’ve started this website to share what I learn with others who are also new to the hobby and want to learn about it. I invite you to sign up for my newsletter and get the free report: 7 Model Train Mistakes To Avoid.


  1. any tips for scaling /sizing custom passenger car decals? i am trying to create my own and need to know the font size and scaling specifications.

  2. Bill Metler says:

    Any suggestion nfor removing the existing pre-painted lettering on a car so that you can decal it to custom fit your layout?

  3. I am decaling a wood box car. I’ve read the article. Should I dull coat the air brushed model before decaling??

  4. I cut the decal out with a little extra space on one side. With my hobby knife, I lightly score the decal in between this extra space and the decal image. I hold the decal with my tweezers on this extra part. This way, I can slide the decal off the paper easily while holding it with the tweezers. It is important to make the score line smooth, without jagged edges so that you do not risk a tear in the decal film.

  5. Mike Mottler says:

    Glad I found your web info about decals. I want to re-number a series of 10 Rock Island metal-clad O-gauge boxcars (20060 thru 20069) to match the prototype cars. Since the boxcar surface is aluminum (not plastic), I wonder … will the PC-printed paper-backed decals will stay put?

    Mike M.

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