An advice on cleaning any oil painting tats covered in dust or yellowed varnish has to come with a qualified disclaimer. More than other types of rough and ready projects, cleaning oil paintings need to be really trusted to specialist conservators. However, if you’re painting is not that old, not offensively precious, or not too significant, there are a few likely ways to make it look brighter and spot less yourself. In addition, changing true antiques almost forever decreases their value, whether or not they look better to you.
If it seems that your painting is little older, evaluate whether the paint is in good shape but the varnish is quite aged. In this case, try applying a gentle solvent called conservation liquid. Art supply stores may sell an "emulsion" planned to clean and take away varnish. There is forever a chance that the solvent would also damage or take away the oil paint. If you are ready to risk this option, wipe the mix with a cotton swab very carefully. Try spot-testing one bend before moving on to the whole canvas. Work in an area with sufficient ventilation.
For recent paintings, your problem is more probable a build-up of dirt, smoke, pet hair, dander, and as well bacterial or any fungal growth. In this case, ensure none of the paint is prepared to come off the canvas or board, meaning that it doesn't show any cracks or any flakes. Then you could cautiously dust the surface with an extremely spongy and dry bristle brush, such as a baby toothbrush or shaving cream brush.
When the surface is muggy, dirty, or oily, you might want to take the attack a step further and in fact uses a gentle detergent solution. Again, usually speaking, oil and water must never mix, as moisture could for sure damage both the canvas and the impasto. Proceeding with care, use brand new fiber cloths dipped in a mixture of dish soap and humid water. Lightly spot the surface, but do not scrub, clean, or rub at the painting. At no point should you sink any part of the painting, nor allow so much damp that it drips or pools.
