We get more questions about varnishing than with any other stage of the painting process.
Varnishing should be an almost mechanical process undertaken to give your painting a protective coating with the surface quality you prefer (gloss, satin, etc.) and possibly an enhancement of colour contrast. But, if you leave it till the last moment and use a varnish you are not used to, you can ruin the work you are trying to protect.
Anxiety and disappointment can be avoided easily if you do sample pieces using the same materials as the painting and varnish them, not the painting, until you get the effect you wanted.
Water-based varnishes are tricky to apply and not removable if you dislike the effect, so we suggest they should only be used by artists who have already tried the above experiment.
Chroma Solvent Finishing Varnishes
We recommend and prefer our Chroma Solvent Finishing Varnishes, because they can be used on all our Chroma paint brands, Atelier Interactive, Jo Sonja’s or Archival Oils.
Application of all these varnishes is by brush (a broad house paint brush), and clean up is with mineral spirits. If applying multiple coats, allow 24 hours drying time between applications. Choose from these finishes:
Gloss Solvent Finishing Varnish
Apply as is for a full gloss, usually one coat. To reduce gloss add Invisible Varnish to your taste. Try 2 parts varnish to 1 part Invisible Varnish, up to 1:1 for less sheen.
NOTE: The new varnishes have an anti-mould additive which is diluted if you add turpentine, so to maintain the mould protection for tropical conditions dilute with Invisible Varnish instead.
Satin Solvent Finishing Varnish
This is our most popular, most unobtrusive varnish.
- The satin finish contains a matting agent and the container needs to be shaken before use to make sure it is evenly suspended. For full bottles: remove some varnish so you can shake the contents easily, then return to the full bottle before using.
- Satin varnishes should not be diluted with turpentine because the ratio of matting agent within the varnish is critical to maintain a true satin finish. Adding turpentine will increase the sheen, however for a satin/gloss finish we recommend diluting the gloss varnish as described above.
Invisible Solvent Finishing Varnish
This varnish offers mould protection without altering the look of the painting.
- Use only one application of this varnish.
- It can also be used on oil paintings as a “retouch” varnish, while waiting out the advisable 3-6 month period for an oil painting to cure before applying a heavier protective varnish.
- On acrylics it can be used for mould protection. It does not alter the appearance of matte surfaces and does not stain paper.
- If you are using any Chroma Solvent Varnish, you can varnish uncured Atelier Interactive paintings.
NOTE: If you wish to preserve the unique velvety matte surface quality of Atelier Free Flow, do not varnish Atelier Free Flow paintings.
This is an attractive feature of all these solvent varnishes, which can be cleaned at some later date by swabbing with mineral spirits.
Water-Based Acrylic Varnishes - Popular But Difficult To Use
We get more distressed phone calls about water-based varnishes which did not behave as expected, than on any other subject.
- All water-based varnishes are non-removable. Solvents like acetone will remove them, but will also remove the painting.
- Water-based varnishes are much more difficult to apply evenly than the turpentine-based ones, and there is always some apprehension when varnishing. We recommend water-based varnishes should always be tried out first on a sample before used on a finished painting because once applied they can’t be removed.
- Do not over brush when applying varnish as this can leave brush marks.
- Water-based varnishes can remain milky for a long time if some of the water gets trapped in the varnish layer. Placing near a heat source will usually fix this problem.
- Water should not be added to the satin or matte varnishes.
Atelier Universal Medium/Varnish
This is a new varnish and offers several advantages.
Use as a Medium
It is very liquid and can be added to the paint for fast-drying, thin layering techniques, but its main use is for varnishing.
Use as a Varnish
- This new product used as a finishing varnish is the only water-based varnish that we know of which is equal in its finish to a solvent-based varnish and is also very easy to apply. We recommend diluting the first coat about 1:1 with water, which allows the painting to absorb the extra liquid easily, and when this has dried it enhances the colours without adding much gloss and is sometimes preferred to a satin varnish containing a flatting agent.
- If a more glossy finish is desired the next layer or layers can be applied quickly and easily because the liquid varnish spreads readily over the sealed surface and can even be overbrushed without problems. Allow about 30 minutes between coats.
How To Apply
- Use a large brush and set the painting on a gentle slope to catch any excess varnish which will run downwards because it is very liquid.
- Do not worry if the surface seems slightly tacky. It will firm up over a couple of weeks curing.
- If you are pressed for time in doubtful weather we recommend the Chroma Solvent Varnishes.