Choosing the right varnish

Varnishing is a necessary evil as far as I'm concerned. It is definitely the part of creating work that I dislike. For many years I used whatever was handy and I honestly didn't know what types were appropriate for my needs. Last year I decided to develop a consistent approach, read about the products and use them accordingly. Because I already used Liquitex Gloss Medium and Varnish for many things, I decided I would stick with Liquitex varnishes. I did read product information for Golden varnishes for comparison purposes and I have used both over the years.

The Facts

Removable v.s. Non-removable
Many acrylic varnishes are permanent and non-removable. Once applied it is there for good. This becomes an issue with conservators if work needs to be cleaned (not in my lifetime).

Flexible v.s. Rigid
Certain varnishes labelled rigid can only be used on rigid surfaces such as wood, hardboards, etc. whereas, flexible varnishes can be used on any surface including rigid ones.

Liquitex Permanent Flexible varnishes (Non - removable)

Types:
Gloss Varnish
Gloss Medium and Varnish
Matt Permanent Varnish

Characteristics:

• 100% acrylic polymer , water soluble
• dry to non tacky finish which is flexible
• non-yellowing
• allows moisture to pass through
• doesn't crack as surface expands and contracts
• suitable for every surface (flexible and inflexible)
• possible to do touch ups over permanent varnish
  

Liquitex Permanent Rigid Varnishes

Types:
High Gloss Permanent (Rigid Surface)
Satin Permanent Varnish (Rigid Surface)

These varnishes will crack on flexible surfaces . They only work on wood, masonite, ceramic plate and other rigid surfaces. Do not use on canvas or paper.

Liquitex Soluvar Removable V arnishes

Types:
Soluvar Gloss Final Picture Varnish
Soluvar Matte Final Picture Varnish

Characteristics:

• solvent based
  
• can intermix gloss and matt for a satin finish
• can be used over oil painting also
• can be thinned with mineral spirits or turpentine
• self- leveling
• flexible, won't crack as surface expands or contracts
• non-yellowing
• contains UV light inhibitiors that resist colour fading
• while you may do touch ups over dry Soluvar in both oil and acrylic, if the painting is ever cleaned the additions will come off.
  

Varnishing Tips

Brushes
Use a wide , soft haired brush (1-4 inches depending on size of painting). Match the size of brush to the size of painting. It is a good idea to keep separate brushes for varnishing. Rollers and sponges are not recommended because they cause bubbling.

Coats
Do not apply varnish until the painting has cured ( 48 - 72 hours) Apply varnishes in 1-3 thin coats rather than 1 thick one which takes longer to dry, may dry cloudy and possibly drip and show brush marks. Most varnishes for acrylics may be thinned slightly with distilled water to enhance penetration and application.

Application
Do not shake varnish or stir it vigorously because it created bubbles.

Apply by slightly overlapping the previous strokes using both a horizonal and vertical motion , so that the entire surface is covered.Do not rework areas missed because you can pick up partially dried varnish and this can cause clouding. Wait until the next coat to solve the problem.

It you are using matt or satin varnish use only 1-2 thin coats to prevent clouding. If you feel you want more than 2 coats start with a gloss varnish and finish with a top coat of satin or matt.

If you have a highly textured surface, apply varnish slowly and try not to let too much varnish settle in grooves or get caught up in grids etc. Microbubbles occur in heavy applications when varnish pools, causes fogging over dark colours.