How to thin miniature paints, and how to make a wet palette

On this page

• How thin is thin enough?
• Two thin coats
• Water, medium or thinner?
• How to make a wet palette
• Common mistakes
• Questions

How thin is thin enough?

There is no single ratio, because every brand and every pot is different: a new pot is thinner than one that has been open for a year, and pigments vary even within a range. So judge by how the paint behaves, not by counting drops. The common descriptions are:

A quick test: pull the loaded brush across your palette or a thumbnail. Basecoat paint should leave a solid stripe that settles flat in a second or two. Layer paint should leave a stripe you can just about see through. If the paint beads up, runs away from the brush or pools like a wash, it is too thin for the job.

Two thin coats

The phrase you will hear most is "two thin coats". Two thin coats that each cover about 70% dry smooth and flat; one thick coat that covers in one go dries lumpy and fills in detail. Let the first coat dry completely before the second (it goes matt when it is dry), and don't worry if it looks streaky. The second coat evens it out.

Light colours over dark (yellow, white, light grey, many reds) need more coats. Rather than thickening the paint, basecoat them over a lighter primer or a mid-tone undercoat: yellow over a light brown or bone, red over a dark red-brown, white over light grey.

Water, medium or thinner?

• Clean water is all you need for most brush work. Tap water is fine in most places; use distilled or filtered water if yours is very hard and you see a chalky film.
• Mediums thin the paint without diluting the binder, so very thin coats still stick and dry smoothly instead of breaking up. Glaze, lahmian, contrast and speedpaint mediums all do this; Shading Medium and Blending Medium are two on the site. Use them for glazes and very thin layers.
• Flow improver breaks surface tension so paint flows into recesses and off the brush tip, and slows drying. Add a little, never a lot: Flow Improver is a common one.
• Airbrush thinner is made for spraying: water, medium and flow improver in one, such as Airbrush Thinner. It is also a good all-purpose thinner for the brush.
• Retarder slows drying, which helps with wet blending and in hot or dry rooms.

Don't thin metallics with too much water: the flakes separate from the binder and you get a patchy, grey finish. Thin them with a medium, or only a little water. Contrast and speed paints should be thinned with their own medium, not water, or they stop flowing evenly (see contrast and speed paints).

How to make a wet palette

A wet palette is a shallow box with a damp sponge under a sheet of paper. The paper lets just enough water through to keep the paint on top wet for hours, so thinned paint doesn't dry out while you work and you can come back to a colour or mix later. It is cheap to make and it is the single biggest upgrade for most beginners.

1. Take a shallow airtight plastic box, such as a food container. Wider is better than deeper.
2. Cut a thin kitchen sponge, or a few sheets of folded kitchen roll, to fit the bottom.
3. Soak the sponge in clean water, then squeeze it until it is damp but not dripping.
4. Cut a sheet of baking parchment (greaseproof paper) to size. Soak it in warm water for a few minutes so it lies flat, then lay it on the sponge and smooth out the bubbles. Hydrofoil or a palette maker's membrane paper works the same way and lasts longer.
5. Put small dots of paint on the paper. They stay wet; add a drop of water to thin them, and mix on the paper.
6. Close the lid between sessions. The paint stays usable for a day or more.

Getting it right

• If the paint goes runny and spreads out, the sponge is too wet: squeeze some water out.
• If the paint dries out, it is too dry: add a little water to the sponge, not on top of the paper.
• Some parchment is waxed or coated and makes paint bead up. Try another brand if paint won't sit on it.
• Change the water and rinse the sponge every week or two, and replace the paper when it is full. A dirty, warm wet palette will grow mould.
• Thin on the wet palette, but load drybrushes from a dry surface, such as a tile or a pot lid.

Common mistakes

• Thinning by counting drops. Every pot is different; check how the paint flows instead.
• Thinning so much the paint stops being paint. If it pools in the recesses like a wash, or the colour breaks up into blotches, add more paint or use a medium.
• Loading too much paint on the brush. Even thin paint floods detail if the brush is overloaded. Touch the side of the brush on kitchen roll before it goes on the model.
• Using the same water pot to thin and to rinse. Keep a second pot of clean water just for thinning.
• Shaking paint after opening it. Shake or stir before you open it, so the pigment is mixed back in.