THIN YOUR PAINTS
"THIN YOUR PAINTS" is far and away the most commonly offered painting-related criticism seen on /tg/, mostly seen in reference to some new Warhammer 40,000 player's fuzzy photographs of his first attempts to paint a model. The second most common appears to be "YOU PUT THE FUCKING PAULDRONS ON THE WRONG WAY ROUND", since new players are inevitably playing Space Marines. Trolling or not, "thin your paints!" is almost always good advice to give a new painter. However, the phrase has reached the point where it gets posted whenever something
badly painted is shown on /tg/.
THINNING YOUR PAINTS FOR DUMMIES
In all seriousness, the most basic paint thinner for your miniature needs is tap water. Really, that's it. Thinner paint basically means lesser consistency. The less the paint's consistency is, the less messy it looks and the easier it is to manipulate while brushing.
The water-to-paint ratio pretty much depends on your preferences and needs; painting a single, normal-sized mini would probably just require you to dip your brush into a cup of water every time you apply a stroke of paint, while painting entire squads or armies may warrant a bit of experimentation with the ratios and the creation of some sizable batches for convenience. Also, note that more water means thinner paint and a longer drying time, and too much water can ruin your paint's consistency entirely, so be careful when thinning large amounts or else you could be wasting time and money. It's a good idea to apply the water to the paint with an eye dropper one drip at a time so you can carefully control how thin it gets.
The more intermediate thinners for painting minis are extenders and flow improvers, which are available in most art stores. They'll also cost you quite a bit if you're planning to paint an entire army. But on the upside, those products warrant much better results than ordinary tap water.
As a last resort, you may actually save some of the details of an over-painted mini by using Nuln Oil shader or something similar. Ultimately if you feel like it's not worth the effort, some first aid alcohol and a toothbrush may help you bring your mini back to its unpainted state without destroying it in the process.
As of 0 M3.016, The only, best and definitive way to ensure that no matter how badly you paint; thicker than a valhallan coat or thinner than a Blood Raven's legs, Prisma is a mobile app that can alter pictures of your miniatures to make them more/less pleasing to the eye. This will cause ungodly rage among most fa/tg/uys, so be warned.
Games Workshop Agrees!
As of 7th Edition, Games Workshop has begun a series of "How to Paint" tutorials with their newest models and factions, helping newcomers into the art of thinning their paints. Everything in the videos are, of course, GW equipment, but at least Duncan Rhodes, the painter in question, show the audience how to properly use it, and what paints need a little work to get to work properly. The videos are fairly simple, but utilize a lot of different paints to get a great result (and earn some money for the Man).
Duncan is also a great believer of THINNING YOUR PAINTS, as his mantra goes: "Put sum paint on ya palet, and then add a lil' drop of waer, ya dun't need very much, just a lil' dip, just. Like... that." and: "You don't need very much, just...yeah...so that it goes nice and smoothly on your miniature."
The real reason for this belief has finally been revealed, thanks to the new Warhammer Community website. Duncan botched up his first model he painted (a custom chapter called the Void Bringers) because "Clearly, I did not thin my paint, nor did I apply multiple thin coats!" Look upon the article, ye mighty, and despair: http://www.warhammer-community.com/2016/11/14/my-first-model-part-1-our-own-duncan-rhodes/
Expect huge amounts of derp and rage, punctuated by /tg/ extracting humor from it.
A lot of the examples in the gallery were painted by this chucklefuck who also appears to be a furry.(don't ask us why there are compliments in the comments. We don't know either.)
And somehow DeviantArt users found a way to get even worse.
I see you! Uploaded by https://m.facebook.com/OoOoOomonkey?ref=bookmarks bought these on eBay.
Ultramarines truly worthy of their spiritual liege.
This one's from a professional painting service. Great work on the detailing, shit work with the face. That's GW for you.
Sicarius, supreme Ultra Marine fighting for the spiritual liege. Do make note of his fabulous leopard print loincloth.
BROTHER LIBRARIAN I CAN FEEL MY FACE SLOUGHING OFF (to be fair these are super tiny models. Those are pens that they're sitting on. Looks like a problem with the undercoat more than anything.)
By the GOD-EMPEROR. Did the guy stick his face inside a heavy flamer?
Catachan is well known for its' unexpected and sudden Acid Rains.
How could you fuck up the Battlesuit as well? That's like, an achievement all of it's own!
It takes a certain mindset, to join the vile Tau Xenos. But that Kroot gun with a chainblade bayonet looks pretty cool.
Paint thinned? Maybe. Astrocious painting? Indeed.
Somebody wanted $40 for this model. Because it's "professionally painted".
Even Duncan Rhodes had to start somewhere.