Modelling Tip: What to watch out for when applying decals

Decals, or transfers, provide one of the finishing touches to a plastic scale model project. Decals have been around in one form or another for over a hundred years and were originally developed for use in decorating ceramics. Those used in plastic kit modelling are typically water-slide decals and if you want to learn more about their history and how they are made click on the links below.

• http://ceramicdecals.org/History_of_Decals.html
• http://en.wikipedia.org/wiki/Decal
• http://en.wikipedia.org/wiki/Water_slide_decal

Decals come in all shapes and sizes and quality can also vary a lot, resulting in problems ranging from silvering, poor adhesion and tearing.
In theory applying a decal is really very easy. Simply cut out the decal you want to apply, soak it in water just above room temperature for a few seconds, lift the backing paper with the decal still on it out the water with a pair of tweezers, maneuvre the decal backing to the location on the model where the decal needs to go, and using a soft tipped tool slide the decal off the backing and onto the model surface. While there is still plenty of moisture under the decal  gently move it to its final resting place. Then wick away the excess moisture with a paper towel or cotton bud.
However, despite its apparent simplicity there are a number of pitfalls to watch out for. Below are a few issues that I can think of and work-around solutions.

• Make sure you apply a coat of gloss varnish to the model surface. This is because decals adhere to a gloss surface much better than a matt surface. If you don't, microscopic air bubbles will be trapped under the surface of the decal and give it a cloudy, silvery appearance. A surface painted with gloss paint or varnish has a much smoother surface.
• Plan you decal application project carefully. Make absolutely sure you know where each is due to be applied before you put the decal in water to soak.
• Have your model in a position that allows you to transfer of the decal to the surface in a comfortable manner. In other words hold the model in place with some sort of hands-free device or method so that you have both hands free to concentrate on applying the decal. I often use Blu Tack or helping hands.
• Only apply one decal at a time. By all means cut a number of decals out of the backing but only soak one at a time. If you do soak too many at a time you may end up over-soaking, causing the transfer to become very delicate and also float off the backing paper. Catching a floating decal is difficult at the best of times.
• Use a decal setting solution to prepare the surface and soften the decal so that it hugs the contours of the model surface better.
• Make sure you do not apply too much decal softening solution as it can melt or dissolve the decal. If this happens, often manifested by a rippling effect on the surface, do not touch it. Simply leave it and let the decal dry out. Obviously this approach is only appropriate if the decal is in the right location. The ripples should vanish of their own accord.
• Instead of sliding the decal off the backing, let the edge of the decal catch the surface of the model and slide the backing from underneath the decal. I find this gives me more control.
• Use the corner of a piece of kitchen towel or a cotton bud to wick away the excess water. If the decal is tough, I sometimes place a piece of paper kitchen towel over the decal and apply a reasonable amount of pressure with my thumb, taking great care not to apply any lateral movement, to help the decal hug the surface contours. N.B. Be very careful doing this when you have used decal softener. Probably best not done in this situation.
• If bubbles appear under the decal surface and cannot be removed by gently pressing, simply prick them with a sharp scalpel blade point or a sharp needle. Then press down gently to release the air from the pocket or roll a cotton bud over the bubble to force the air out. A coat of decal solution can then be applied to help remove any evidence of a cut or hole.
• When the decal has thoroughly dried apply a coat of varnish to seal it for good and to stop it lifting off the model as it ages.
• Sometimes old decals crack or turn yellow, however it is possible to restore them. The yellowing can be fixed by leaving the decals in the sun (e.g. on a window sill) to bleach and once this has worked apply a coat of Microscale Liquid Decal Film to rejuvenate the decal itself.

That is about it. If you have any decalling tips, get in touch using the contact us page.