This article was originally published in the May edition of the JoeCanuck Newsletter.
Joes and Alcohol
I cannot express to you the importance of thinning down your paint so it goes on smoother. If you're using acrylic paint like you should (hisses like Dracula confronted with a stake at the thought of enamels), then you're probably already thinning down your paint with water when you apply it. This will be done in a very similar fashion.
JoeCustoms member J_Man brought up the idea on the forum of using Isopropyl Alcohol (aka rubbing alcohol) to thin down paint. I had heard others talk about doing it but until I read that a cheap bottle of rubbing alcohol could help, I invested the $2 to try it. You see, isopropyl, is a solvent, with one of its many uses is as a paint remover.
The way we're going to use it is to make the paint apply more evenly over the surface of a figure, giving it a light smooth coat. Also in this example I'm using white over a yellow color plastic to really show the difference. The main idea here is to replace the water you would have used with the rubbing alcohol with 70-91% isopropanol. Start by pouring the rubbing alcohol in your container. Since the alcohol evaporates much quicker than water (another reason why it helps the paint go on smoother), I use containers that have lids, like a medicine bottle or baby food jar.
Next, put a drop or two of rubbing alcohol in the paint you're about to use. I also let the brushes I'm about to use soak in the container to loosen the bristles, but this isn't necessary.
Now you are ready to apply paint. Using smooth even strokes paint the parts of the figure. Remember to re-submerge the brush in the rubbing alcohol every once in a while when you reach to put more paint on it. When you see any build up of paint on the tip of your brush, re-submerge it, and wipe clean with a paper towel. The biggest tip I can give is to do multiple thin layers of paint with drying time in between rather than a thick layer at once. With the thinned paint you won't have much choice in the matter. I painted the left leg (when looking at the pics) using the alcohol and without alcohol for the right leg. As you can see the left leg looks much smoother.
Epilogue After this article was written, and during one of the hottest summers on record, I started adding a little water to my paint bottles. My paint was simply drying out out before I could get a chance to use it. When done in combination with thinning with alcohol, the paint has never been smoother.