I am an artist who is always exploring different materials, tools, and processes.
The Appeal of Matte Finishes
Why use a matte finish? Although a polished gloss finish can be mouth-watering, so much reflecting light can be a distraction. A matte or satin color can look more saturated and can look the same from all visual angles.
Besides aesthetics, there is a very practical reason to want a matte finish. A matte finish will facilitate painting a different color on top. That is because the uneven light-scattering surface provides tooth for other coatings to adhere to.
The Sheen of Paint Is a Delicate Balance
Whether a paint dries glossy, satin, or flat is determined by the surface of the paint film on a microscopic level. A smooth surface without pigment particles protruding outwards would be very glossy, reflecting light. On the other hand, a bumpy surface with pigment edges would scatter light and produce a matte finish. In this article, I cover methods that will produce a paint finish that scatters light instead of a real glossy one.
Method 1: Scuff With Fine Sandpaper or a Scotchbrite Pad
Probably the easiest way to make a glossy paint flat or satin would be to sand it by hand. Wet or dry sandpaper 300 grit or finer is best.
Another option is using a Scotch-Brite pad. Be especially careful on outer edges and corners not to remove too much paint. A light, delicate touch is what is required here. I recommend wet sanding because the finish will be more even, and the sandpaper won’t get clogged up so easily.
Method 2: Spray From a Farther Distance
Whether using a finishing product from a spray can or a spray gun run by a compressor, simply spraying from a longer distance gives you at least a satin—if not matte—finish.
What happens is: The paint partially dries in before reaching the surface with little to no flow, so an uneven finish is produced. It's better to do this with many very light misting coats to minimize the orange peel effect.
This could also be a technique for clear lacquer coats. The solvents in lacquer evaporate rapidly, and it would still be crystal clear. Many satin clear coat lacquers have silica as a matting agent. Satin clear can be tricky to apply without getting a cloudy uneven finish. I'd rather work with perfectly clear gloss and spray real light from a distance and sand any areas that do get shiny.
Method 3: Apply a Solvent to Dried Paint
The method of dabbing a fully dried gloss paint film with solvent on a rag may be best for situations where an object is to be refinished, and dust from sanding is to be avoided. This would be especially true if painting over a finish with a toxic pigment containing lead or cadmium, for example.
You can even go to a well-stocked home improvement center and find over the counter paint deglosser or liquid sander. These contain a myriad of solvents, detergents, and possibly alkaline additives. But rest assured knowing you don’t have to buy these one-trick-pony products if you have solvents already.
For water-based emulsion paint films, you can degloss simply with denatured alcohol or rubbing alcohol. You can use xylene, varnish, and paint makers naphtha or mineral spirit for more durable alkyd and other solvent-based paints. If the toxicity of aromatics like xylene is a concern, adding a little acetone to mineral spirits could also be used.
NOTE: Apply to the inconspicuous area first, and don’t rub too hard, or paint might be damaged. Also, some of the paint colors will come off, so it is advisable to leave the painted object alone for at least an hour after deglossing before a wipe down with a clean towel and application of the next finish.
Method 4: Add More Pigment to Medium
If you are making paint from scratch, starting with dry pigment, increasing the pigment load should be sufficient for getting a matte finish. While mulling a pigment dispersion with glass muller and slab, take half of your dispersed pigment and add just enough medium to get a semigloss paint by testing with paint swatches. Then add the remaining portion of dispersion until the desired sheen of the paint film is made.
Inorganic mineral-type pigments like chromium oxide green and red iron oxide make good matte paints. Inorganic mineral pigments have larger-sized particles, and higher amounts can be mixed with paint binder.
There are practical limits on how much pigment you can add, though. Too much pigment and the paint film will drastically lose durability and rub off more easily.
Method 5: Use Fillers and Pigment Extenders
Although adding additional pigment might be the simplest method for making paint, adding a filler is best for ready-made paint products. Several inexpensive materials can alter the sheen and even the texture of paints.
In fact, chalk paints are all the rave with furniture refinishers. Chalk paints are simply emulsion paints with calcium carbonate powder added to give tooth to the paint. What makes these paints wildly popular is that the furniture does not need to be sanded down. Other chalky substances like plaster and diatomaceous earth are also used.
Some other possibilities for matting agents are baryte, talc, and silica. Making a paint simply matte requires less matting agent than what a chalk paint requires. It might be advantageous to make your own matte medium with one of these powders completely dispersed in the clear medium of your choosing. Then mix your DIY medium gradually with your paint. That way, it would be easier to control the addition of a matting agent.