If you have used a natural lime, chalk, mineral or silicate paint and noticed tiny dried flecks or "bits" in the tin, or picked up by your brush or roller, this guide explains why it happens. In almost every case it is a normal characteristic of mineral paints rather than a fault with the paint, and it does not affect the durability or the finished look of your walls.
The short version
Traditional mineral paints, including silicate paints, lime and chalk based paints and other mineral paints for walls, are made from natural minerals and water, without the plastic co-binders found in conventional acrylic and vinyl emulsions. Those plastics are very good at holding everything in a smooth, stable suspension. Mineral paints behave a little differently, and one side effect is that small dried particles can occasionally form. It is a sign of what the paint is, not a sign that anything is wrong.
Why the bits form
- Fast surface drying. Mineral paints dry by reacting with air and, in the case of lime, with carbon dioxide. Wherever the paint meets air, around the rim of the tin, under the lid, or as a thin skin on the surface, it can begin to dry and form small hard flecks. When you stir or pour, those flecks drop back into the liquid paint and get picked up by the brush or roller.
- Natural mineral fillers. The pigments and fillers are ground natural minerals rather than uniform synthetic particles, so a small amount can settle or lightly clump, especially if a tin has been standing for a while.
- Opening and resealing. Every time a tin is opened, a little more air reaches the paint and dried material can build up around the lid seal. This is why the same thing can happen across two different tins, and in both a plastic tub and a metal tin.
Why some of your other paints were fine
Not all breathable paints behave the same way. Some mineral and mineral hybrid paints, such as Graphenstone Grafclean Premium Matt, have a slightly different formulation and tend to stay very smooth, while conventional paints from other suppliers use plastic binders that suppress this effect entirely. So it is quite normal to see small bits in one natural paint and none in another, even when both are painted in the same room on the same day.
How to minimise and deal with the bits
- Wipe the rim before you reseal. Clean any paint from the rim and lid groove each time, and press the lid down firmly so the tin is airtight.
- Stir gently and thoroughly before use, lifting from the bottom, without whipping air into the paint.
- Strain the paint. The most reliable fix is to pour the paint through a fine paint strainer, a kitchen sieve, or a piece of clean muslin or old stocking into a clean paint kettle. This removes any bits before they reach the wall.
- Work from a kettle, not the tin. Decant only what you need and keep the main tin sealed while you paint.
- Lift any stray bits as you go. If a fleck does land on the wall while the paint is still wet, it lifts off easily with the tip of the brush.
Does it affect the finished wall?
No. Once strained or lifted out, the paint applies and cures exactly as intended, with the same breathable, mineral finish. The bits are simply dried paint of the same material, not a contaminant, so they do not change the colour, coverage or long term performance of the wall.
Still not sure?
If you have opened a tin and you are not happy that what you are seeing is normal, we are always glad to help. Send us a photo and your order number and we will take a look. For mould prone rooms our best performing option remains Auro 303 Natural Mould Resistant Silicate Paint, and you can browse the full range of breathable mineral paints for walls whenever you are planning your next project.
