(The dangers of)  Pre-shading with permanent markers

Modelers are always looking for materials and techniques which can speed up each step of model building, and that is good as we don't have time to spare as we used to. Sometimes, however, someone drops by with an interesting tip, something that seems a great finding at first. You decide to use it only to discover, weeks or months later, that that particular trick ruined your latest masterpiece. This article is just about one of such things: pre-shading with permanent markers (or sharpies). And allow me to start by my personal advise on using them to pre-shade your models: don't do it!

Years ago I was building a Spitfire and used a permanent marker to circle spots that needed further sanding. I corrected the signed spots, but I didn't bothered removing the circles because another layer of primer would be necessary. I applied the second layer of primer and, after a few weeks, I noted that the circles were showing through. Not wanting to run any risk, I sanded those areas until all traces of permanent markers were removed. That episode remained in my mind until another model, when I didn't removed the marks. And to my horror, they showed on the top of the camouflage weeks later. It wasn't too late to repair the model, but I decided to study the subject and recalled my college classes of mass diffusion. This is a process where mass particles migrate from a more concentrated medium to the the less concentrated, subjacent one. This is similar to the salt water and drinking water experiment, where both solutions are separated by a membrane. With time, the salt will progressively migrate to the drinking water until the concentration is about the same on both sides of the membrane.

Back to our modeling life, during the last years many modelers have been reporting fast pre-shading on their models using sharpies and similars.

It seemed a good idea: quick and cheap -  you don't have to crank your airbrush up and mess with painting, cleaning and all. This is an example I found on the internet:

The (big) problem is that the permanent marker ink will migrate through all layers of paint until it is visible... No, I don't mean faintly visible, it will look like a punk graffiti. It is the Physics in action:

More recently, many modelers have been reporting sharpie pre-shading bleeding through, and you can find several cases on discussion boards (like here, here, or here). I've been waiting a long time for a chance to record the effects of using permanent markers for pre-shading. Unfortunately, it happened to a friend of mine, despite my several warnings not to do it.

This is Academy's F-89 in 1/72 scale built by Volmir Batista. I watched him working on this model during months. After my warns, he tried to remove the pre-shading but "successful cases" on using the method convinced him to run the risk. Well, here is the model:

You don't find anything wrong with it? Look closer:

It looks like the sharpie was used after the painting, doesn't it? I'm sorry for Volmir, but glad I recoreded it.

For the records, he used automotive primer, Testor Model Master enamel paints and Future as a gloss coat. As you see, no fancy Devil brand products. In fact, this is a quite common recipe among modelers. Volmir called it transmigration, and the name stuck among our club members. Here is another shot of the "The transmigrated", as he refer to it now:

Please, note that the migration will happen provided the marker pigment is small enough. I mean much smaller than the paint pigments. There are many paint brands out there, many clear coats, and I won't claim the problem will happen to all of them. But if it does, it takes some time to happen, maybe weeks or months before it becomes visible, and I will tell from my own experience it is not a good thing to see a black mark on your model surfacing more and more visible day after day.

I also have been reading and listening comments in favor of this technique. Well, the photos are here, it is your model. Permanent markers do are useful tools in modeling, and someone can find another interesting use for it.

Just remember that in this case the old saying "Test it in a piece of scrap before using on your model..." should be appended by "...and wait a few months just to be sure". Not exactly my recipe to speed up model building safely.

I hope you find this tip useful.

Rato Marczak © 2011