There is so much mystery about how to varnish, when to varnish, WHY to varnish, we made a quick tutorial on the wonders and tribulations of varnish. As always, consult your varnish manufacturer for exact instructions.
Manufacturers who produce high quality products will also provide ample literature and information for you about their product, as well as how to apply it and how to remove it. Go here to view our sister company Grumbacher's line of varnishes: http://grumbacher.chartpak.com/categories/mediums/
Whatever path you choose, it is always worth your money to get a high quality varnish from a reputable manufacturer. Not only will it extend the archival quality of your work, but it will be easier to work with and remove.
One of the biggest misconceptions about varnish is that it is a permanent protection. Some varnishes are made to be a removable layer, to be reapplied every 20-50+ years, depending on the quality of the varnish and the harshness of the elements your painting is exposed to. NEVER RUB when removing varnish. When you feel it’s time to remove your varnish, please consult the manufacturer’s instructions. Varnishes vary wildly from place to place, so please check with your specific brand on how to remove their varnish.
Essentially, it will involve a solvent like ammonia, turpentine, or odorless mineral spirits, lots of patience, and a careful hand. Depending on the value of your work and/or your faith in your abilities, it could be worth it to consult a professional art conservator and hire them to remove and reapply your varnish.
GOOD LUCK!
Chartpak Inc. is affiliated with Thalo, LLC