Varnishing Oil Paintings

Hello! Its me Ryan, and it was lovely meeting you during my visit. Here is a page I put together that covers a lot of the varnishing tips we talked about during my lecture, as well as some extra tips!

Important Reminders:

  • Oil Painting must be completely cured before you varnish, this typically takes at least 6-12 months. The thinnest layer of oil paint takes 6 months to dry. (Dry to the touch does not mean it has thoroughly cured. The oil and oil mediums need to oxidize and under go complete polymerization. Only when the oil has completely polymerized, is the oil paint considered permanent, and it is safe to put varnish on). If you have to varnish before the 6 months to protect the painting surface from shipping or traveling or exhibiting in a less safe space, use a retouch varnish. Retouch varnish will still allow the painting to cure slowly, while also protecting the surface (though it will not protect or seal the surface completely or at the strength of a typical varnish).

  • Choose a dust-free area where you can keep windows and doors closed. It’s best practice to varnish on a flat table or work surface – avoid working vertically.

  • Before you start varnishing, gently wipe the surface of the painting with a lint-free cloth to remove dust. Then stir the varnish well and pour it into a clean, flat saucer or tin. Load your brush, then wipe it on the side of the saucer so it’s not dripping.

  • Do NOT pour varnish onto the painting. I know it looks cool (and there are many viral videos of this), but our chemists recommend using a thin, even layer. Tests have shown that pouring the varnish onto the painting results in too much varnish, and uneven distribution or soaking of the varnish into the surface. Pouring directly onto the painting, then brushing it out, can lead to drying issues, or make the finish look uneven. If the varnish goes on too thick, it will not properly dry, and may feel tacky indefinitely.

  • Avoid going back over areas that you’ve done. If there are spots you’ve missed, simply allow the piece to dry completely and revarnish. After you’ve finished, ensure that you shield the work from dust while it dries, using a protective plastic cover known as a tent.

  • Varnish in a well ventilated area to avoid breathing in irritants

  • Allow Varnish to dry completely before wrapping, drying time should be indicated on bottle, typically 24 hours.

  • If not using a Winsor & Newton varnish, be sure the varnish is removable. I highly recommend only using removable varnish in case the varnish goes in uneven or the varnish gets dirty over the years from dust and air pollution.

  • I recommend practicing varnishing on a minor painting first, not on your most prized painting.