A short and sweet tutorial on how to apply water-slide decals or transfers:

For those that may be new to the modelling or radio controlled tank hobbym by far the most commonly used type of deal or transfer is the water-slide variety. Here is a step by step guide taken from the Echelon Fine Detail site on using water-slide transfers.

1. To achieve better result, a gloss or semi-gloss coat is very important. It will make a smooth layer which the decals will suction to and make it much easier to apply and set them.
2. Cut out the decal you need (do it on cutting mat)
3. Grab the decal with tweezers, place it on the surface of the water and leave it for about 20 to 30 seconds. The larger the decal the more time in the water it may need.
4. Remove the decal from the water and place it on paper towel to remove any excess water.
5. Apply a decal solution of your choice to the part where the decal is to be placed. Decal solution is not required on a perfectly flat and prepped surface - but is highly recommended for a better transfer.
6. Slide the decal off the backing paper on to the model. Using a paint brush or cotton bud is a good way to do this without damaging the decal.
7. Use the brush, knife or cotton bud to position the decal. Using your paper towel, gently dab the decal and soak up the excess water (decal softener is also recommended at this stage. After applying softener, the decal will suction to the part and flatten out smooth.)
8. When the decal is completely dry, give another coat of varnish or Klear/Future to seal it.