Skip to content
Rapid Thinner: What is it? How to use it? Why use it?

Rapid Thinner: What is it? How to use it? Why use it?

GSI Creos/Mr. Hobby manufactures many solvent thinners, the most well-known three beyond Mr. Color Technical Thinner, Mr. Color Leveling Thinner and Mr. Color Rapid Thinner.

For most cases, it is sufficient to use just Mr. Color Leveling Thinner or  Mr. Color Technical Thinner, as most colors work best with these thinners. It is safe to say that these thinners are the most versatile. These two will discussed in a future article.

For the scope of this blog post, we will be focusing on Mr. Color Rapid Thinner.
I often get questions about Rapid Thinner, it's always the most elusive of the three. Given that the other two are the most versatile, why would anyone want to use Rapid Thinner? What about it warrants a completely separate product?

Simply put, Rapid Thinner, as the name suggests, has its strength in its fast drying time. The major benefit provided by Rapid Thinner is the faster drying time. For some people, this is great because they don't want to wait so long for their paint to dry. For others, it's not great because they want a slower drying time for a smoother glossier surface.

See how I said slower drying time = smoother glossier surface? That is an important aspect we must discuss. When paint takes a long time to dry, it has a lot of time to "level". Leveling means that the paint has enough time to settle and even out. Think of it as a blob of ketchup looking ripply when you put it on a smooth surface, but return to it in 10 minutes and its spread out and smooth. When a paint levels, it is slowly evening out the peaks and valleys from application when it dries. This results in a much glossier/smoother finish. This effect is afforded by the slower drying times.

Rapid Thinner, as mentioned dries faster, so it doesn't have time to level. Why may that be desirable? It is desirable because matte paints can become even matter and metallics can dry more metallic than glittery.

Matte paints and Metallic Paints have a few things in common. That is, a heavy pigment suspended within a solvent medium. Matting agent is a relatively heavy additive in matte paints that offers the matte finish; metallic pigment are relatively heavy pigments that are suspended in solvent. 

When these particular paints are made to dry quickly, the matting agent does not have time to even out, therefore resulting in a stronger matte finish.
Similarly, when metallic paints are made to dry quickly, the metallic pigment does not have time to settle to the bottom during the process of leveling. This results in a better and even metallic surface rather than what looks like glitter with a clear coat overtop.

As per GSI Creos's description:
"This is a new type thinner dedicated to Mr. Color.
Drying speed when an air brush is used is faster than with the regular thinner, and when metallic paint is used in particular, metallic particles are aligned evenly to produce a neat glossy surface."

Key point is that the metallic particles are aligned evenly rather than leveling to the bottom.

Ultimately, it is up the painter what results they may want to pursue. Some have value for the glittery effect, others prefer the metallizer look. There is not wrong answer. However, it is important to understand the value for certain products and the solution it presents a problem.


Instagram Tool Tip:

To summarize, without the nitty gritty of paint pigment mechanics, Rapid Thinner is designed to dry faster, benefitting metallics and matte-based paints. The results are matte paints being matter and the metallic paints being more metallic and even.

Rapid Thinner is a powerful tool to have in every painters arsenal, as it provides the means to achieve effects not achievable with the other more common products.

Previous article Paint Thinner Guide - What works with which?