Best humidity to prime miniatures

priming miniatures in the right humidity

If you’re getting poor results with your mini priming it could be due to the climate, and the humidity in particular.

When first starting to paint minis, it’s easy to just spray away with the grey, white or black primer and assume a poor finish is down to your technique. At least, that’s what I assumed for a quite some time.

It wasn’t until sometime later that I realised the climate had a lot to answer for.

No, I wasn’t spray painting in the rain 🙂

Back then, I was living in a small village in the middle of a huge area of marshland, a place called Romney Marsh in the South East corner of England for those interested. And the humidity there was invariably high, rarely dropping below 70% if I remember and often much higher.

I rarely got the results I wanted and have since learned this was more than likely due to the humidity being way too high.

Priming at this level plays havoc with the drying process as the moisture in the paint can’t evaporate. I ended up with an uneven finish where the paint dried at different speeds.

I now live in Surrey which has a far more primer-harmonious humidity, with levels consistently around 55% which is near to the ideal 40% to 50% for priming minis and other plastic models. Having said this, I have noticed recently it’s creeping up more than it used to.

So if you’re getting odd results with the primer on your miniatures check your humidity levels. If they’re too high, either move to Surrey 🙂 or putting the minis in a well-ventilated spray booth or get a dehumidifier as I describe here.

A colleague also suggested keeping piles of salt around the mini. I can see how this might help but never tried it. I’d be interested to hear any other suggestions for dealing with humidity if you have them.

> A final, personal, note: I spend a huge amount of time testing, photographing, writing and researching techniques for these articles and pay for all the running costs of MRE out of my own pocket. If you found this article useful you can support me by making a donation on my fund-raising page. Thanks and happy modelling, Andy.


Founder of ModelRailwayEngineer, Andy Leaning

Andy is a lifelong modeler, writer, and founder of He has been building model railways, dioramas, and miniatures for over 20 years. His passion for model making and railways began when he was a child, building his first layout at the age of seven.
Andy’s particular passion is making scenery and structures in 4mm scale, which he sells commercially. He is particularly interested in modelling the railways of South West England during the late Victorian/early Edwardian era, although he also enjoys making sci-fi and fantasy figures and dioramas. His website has won several awards, and he is a member of MERG (Model Railway Electronics Group) and the 009 Society.
When not making models, Andy lives in Surrey with his wife and teenage son. Other interests include history, science fiction, photography, and programming. Read more about Andy.

Afflliate disclosure:The links on this page may take you to carefully selected businesses, such as Hornby, Amazon, eBay and Scale Model Scenery, where you can purchase the product under affiliate programmes. This means I receive a small commission on any orders placed although the price you pay does not change. You can read my full affiliate policy here. I also sell my my own ready to use, pre-made and painted buildings and terrain features. browse the range.

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