Varnish: Tips and Techniques

I have recently polled all my artist friends and researched extensively online to find the best method for getting a perfect finishing varnish on my oil paintings. After lots of practice, I finally have a method that gets great results every time…. Well, almost every time. Varnish is a notoriously tricky procedure!

What is Varnish?

Varnish is the final clear finishing coat applied over a “dry” oil painting. Varnishing seals the surface of the painting, protecting it from dust and dirt build-up. It also restores an all-over sheen to the whole painting, deepening shadows and restoring colors that may have gone matte as the paint dried.

How “Dry” is Dry?

Traditionally, artists waited 6 months to a year before varnishing. And that’s for thin paint! Thick globs of oil paint may actually take many years to dry completely. However, if you are actively showing or selling your work, or working on commission, this is highly impractical to nearly impossible. So, many artists varnish when the painting is “dry to the touch”. There is danger of cracking however, especially if the paint is thick and you are working on flexible canvas.

What Kind of Varnish?

Damar is the traditional varnish used by artists, made from tree resin. However, it is known to yellow with age, and it is also very brittle. Gamblin, manufacturer of paints and mediums, has developed a synthetic-resin varnish called GamVar that has been designed to remain transparent, and also is less brittle. In fact, GamVar says you can apply their varnish when the painting is dry to the touch. Apparently GamVar allows the painting to continue to dry underneath the varnish. Personally, I find GamVar significantly easier to apply, as it stays “brushable” for some time, and does not get tacky within seconds like Damar. So, now I never use Damar, and I only use GamVar.

Removing Varnish

Varnish is made to be removable by anyone in the future cleaning or restoring your painting. It is designed to dissolve easily with odorless mineral spirits (OMS). It’s hard to imagine rubbing OMS or turps on your oil painting, but keep in mind, dry oil paint has a very strong film and won’t simply wipe away with gentle swipes of OMS. So the good news is, if you mess up your varnish, it’s easy to remove and re-apply.

You will need:

• GamVar Varnish
• Sponge brush (Buy several, they are cheap)
• Small shallow dish (larger for a large painting)
• Small soft paintbrush, like a #1 sable filbert
• Low-lint cloth
  (There is no such thing as “lint-free” but do the best you can. I use floursack-style dishcloths, although I recently discovered soft auto-cloths, almost like baby diapers, which I am going to try next.) 

Lint is your Enemy

Lint (and dust) will conspire to flock to your painting in massive unforeseen hoards. The largest airborne bits of debris you have every seen will suddenly appear to hover above your freshly varnished painting in a great, slow mating dance. Your job is to keep lint off your painting, and off everything else that might come in contact with your painting.

Prep

Never varnish the day you ship, frame, or deliver a painting! Give yourself a few days of extra time, both for the sake of the painting, and for your own sanity.

Varnishing with GamVar for the first time takes a bit of advance planning, because it comes in a box with 2 ingredients you must mix together in a jar 8 hours before you use it. The directions say to shake the jar every hour for 8 hours, but I have found this to be impossible - who could do that? So I just shake the jar once or twice over 8 hours, as I think of it, and it has always worked fine.

Once the GamVar is ready to use, take out your dry-to-touch painting and inspect the surface. Use tack-cloth or adhesive tape to remove any dust or lint that has accumulated. If there is a lot, you may want to wipe down the surface gently with a clean, low-lint cloth dipped in a bit of OMS.

Next, set your painting on an easel and shine a lamp on the painting for a good 30 minutes (don’t lie the painting down flat or it will just accumulate more dust). This will evaporate any moisture on the surface. If there is moisture on the surface, the varnish will “bloom” - a horrifying phenomenon, where you may think you have achieved a perfect varnish finish, only to find that within a few hours that the surface has developed a opaque white haze. Don’t let the painting get too hot, but it should warm a bit under the lamp.

Ready, set…. VARNISH

When you ready to apply the varnish, use SPONGE brushes. They are cheap, they don’t leave any stray hairs behind, and best of all you can just throw them away when you are done. I keep a batch of fresh my new ones in a plastic ziplock bag, so they don’t gather dust before use.

Pour a very small amount of GamVar into a clean, lint-free dish. It’s easier to dip the brush in a shallow dish, and also you won’t be contaminating your nice clean varnish jar with the inevitable dust or debris on your brush.

Dip the tip of the sponge brush in the GamVar, and then brush on a thin coat over the painting, using long, horizontal strokes to cover the entire surface. Then, blot (don’t rub) the brush on a clean, low-lint cloth.

Brush again with the slightly dry brush with strokes perpendicular to the first ones. Blot your brush on the towel again.

Repeat over and over, brushing and blotting, in perpendicular strokes, until the surface starts to tack up the tiniest bit, and “grab” the brush. 

This is reducing the glossy shine of the varnish, which can make the painting look too wet, and will make it too shiny, especially under bright gallery lighting.

Waiter, There’s a Fly in my Soup!

What to do when you get lint in your varnish: Use the small #1 filbert to carefully “back brush” and lift the lint out with one swift flick, and wipe on the cloth. If you don’t dig around too much, the varnish should “heal” and there should be no sign you messed with it.

The Inevitable Do-Over

At some point everone has to re-do a varnish job. If you have lots of lint, or bloom, or if the surface was touched or damaged, you’ll have to remove the varnish. To remove, dip your clean lint-free cloth in odorless mineral spirits, and gently wipe (or even roll) the cloth on your painting. Be careful not to damage the painting, but keep in mind, it’s probably more resilient than you think. Dry paint film is pretty strong. Wipe until it seems like all the varnish is gone. If you are not sure, wait a few minutes for the OMS to evaporate, and then look for glossy areas. Start all over again, starting with removing any dust or lint.

Varnishing a smooth painting

My paintings have a pretty smooth surface, which adds another issue to varnishing: Beading up. Sometimes the varnish immediately beads up just like water on a new car. This is because the surface is so smooth that the varnish has nothing to “grab”. You need to get some tooth in your surface. Wipe off the wet varnish with a cloth dipped in OMS. Then brush on a generous coat of OMS, and keep brushing until there is no longer any beading up. You may want to let the painting sit for a while, to let the OMS “bite” into the surface.

Be gentle, don’t rub hard, and the painting should be fine. When a coat of OMS does not bead up, the varnish won’t either. Put your painting under a lamp to evaporate the OMS, and then go ahead and varnish. Now I always brush on a coat of OMS before applying the varnish, to test for beading before I ever try to apply the varnish. NOTE: use one brush for OMS and a different brush for varnish. You don’t want to dilute the varnish with the OMS left on the brush.

Varnishing is tricky, and it’s always a good idea to practice on a small painting you don’t care much about before varnishing your masterpiece.

Good luck! If you have other tips or suggestions, feel free to leave them in the comments. 

Plein Air Setup

Painting outdoors is inspiring, beautiful, centering, and so adrenaline-rushing as to be addictive!

However, it is also uncomfortable, frustrating, full of distractions, and when your umbrella topples your easel over in a breeze, exceptionally maddening.

I have finally assembled a setup I find to be ideal - a good balance of lightweight, sturdy, and flexible:

    

• Open Box M pochade box 10x12
  
• Julienne painter's umbrella
  
• Manfrotto tripod with joystick head
  
• Manfrotto jointed arm that clamps directly to the tripod and holds the umbrella securely at any angle, with clamps at either end for grasping the easel and the umbrella handle. NOTE: Amazon sells the arm, but not the clamps, so call Open Box M to order through them.
  
• I also have a lightweight walking cane that folds open into a small stool, which I got here at Bed Bath and Beyond
  
• I also find these small things essential:
  Seal-able solvent can
  Viewfinder
  
• This accessory I have not bought yet, but I see how it could come in handy

This is how I pack it:
Instead of carrying around tubes of oil paint, I load up my Open M pallete with fresh nuggets of paint before I leave for the day. Sometimes I pack a small tube of white, if it's going to be a long day out.

I can fit my Open M pochade box, brushes, and solvent can in a backpack or shoulder bag, along with paper towels, lunch, etc.

The tripod, cane, Manfrotto arm, and umbrella I lash together with 2 short bungee cords. All those things combined are not very heavy, and I can carry it by the cane handle, or under my arm easily. For a long hike I might get a strap for it so I can carry it on my back.

Travelling with oil paints
I have traveled now many times with oil paint, and despite the horror stories we have all heard about having oil paints confiscated, I have never had a problem with this procedure:

Here is what I do:

• Download and print a couple "material safety data sheets" (MSDS) which describe the contents of the paint - there's a different sheet for every color, but I just choose 2 or 3 and print those. Each manfacturer writes up and makes data sheets available online as PDF for all their colors, just google search one your paint brands and a color name with the phrase "material safety data sheets" and you'll find it.
  Here is a list of links to of many of the of MSDS paint brands
  
• Print out a sign with big font that says:
  These are vegetable oil based artists materials.
  They are not flammable.
  Data sheets enclosed.
  DO NOT USE THE WORD "PAINT". The word paint is a big problem.
  
• Fold the MSDS sheets and the sign together so the big message shows up on top.
  
• Put all the tubes of oil paint in a gallon-sized heavy duty ziplock, and put in the folded packet of sheets so the sign is visible through the plastic bag. Make sure every tube is tightly-capped and there are not any holes in any of the tubes, the pressure changes during the flight will make a mess of any leaky tubes.
  
• Place the bag near the top of your suitcase with the sign-side up so it's immediately accessible if security searches my bag. (I always get that little note saying they searched my bag, but my paint has never been confiscated.)
  
• Check the bag. I wouldn't try to bring paints on board.
  
• I also packed a tiny tin of the "natural turpenoid" (in the GREEN can) along with my painting supplies in my checked bag, to use as my medium. It says non-flammable very clearly right on the tin. I wouldn't use it as a medium in major paintings, but for sketches and all prima work while travelling it's probably fine.
  
• I wouldn't bring any solvents, oils, mediums, or any kind of mysterious liquids in bottles. I usually buy those or borrow them when I arrive
  
• Finally: Don't forget your palette knife! :)

Hope that helps! It would be terrible if the paints got confiscated and that's always a risk, so I can't guarantee it will be fine, but it's worked for me.

Home-Cooked Gesso Part II

My materials for making home-made gesso.

Clockwise from left:

2 nested pots on a portable electric burner, metal mixing bowl and wooden spoon, Sinopia brand Titanium White pigment (so glad I bought two jars!), small power sander, bag of marble dust. Not shown: ArtBoard brand panels, housepainting brush, large tupperware

I bought everything at a hardware store and art supply store; the pots and bowls I stole from my own kitchen - not to be used for food again.

I previously wrote a post about making my own gesso. This new post shares my notes based on my most recent batch: This week I prepped over 30 very small panels for my students.

The instructions below are based on the recipe and steps outlined on the Sinopia website, but I added all the tips and tricks I discovered along the way (my notes are in italics):

Preparing Glue Size (Rabbit Skin Glue) DAY ONE AND TWO

• Soak one measure (by volume) of glue to 12 measures of cold water
• I used 1/4 cup RSG to 3 cups water in a big tupperware container I do not plan to use for food again
• Allow glue to soak preferably overnight
• The next day it is a gelatenous substance.
• Heat glue mixture in a double boiler bath - I don't have a double boiler, so I just nested two pots together which worked fine: I boiled a half-pot of water on a portable electric burner in my studio, and nested a smaller pot inside. The smaller pot is non-stick. The glue melts and becomes liquid very easily.
• Apply glue while warm with a flat brush - I used a housepainting brush, but a softer art brush is probably better.
• Be warned: this is makes sticky mess, since you need to cover the panel on all sides and there is nowhere to hold onto it. I discovered this method works best:
• Hold the panel from underneath on your fingertips, like a waiter holding a tray, and then brush the glue onto the (top) painting surface and edges.
• Lean the panel against a wall, so just the top edge or corner is touching, and them gently brush glue on the back side. (I scored and folded foamcore to protect my wall and floor)
• Usually two layers are enough to seal the wood effectively. It dries fast, in about an hour or less I could do the second coat. Then I let the panels dry overnight.
• At this point it is advisable to adhere a piece of fabric (thin muslin sheeting) to the panel to help stabilize the ground and to protect it from joints in the panel that might show in the gesso. (I did not do this - I like my painting surface to be very smooth and I didn't want the cloth texture.)
• The left over glue-size then gets used for the chalk ground.
• NOTE: The RSG turns to jelly again if you let it cool, it firms up quite a bit of you leave it to cool overnight, but you can re-heat the next day, it works fine.

Chalk Grounds: Ingredients DAY THREE, FOUR, FIVE....

3 parts of glue size (by volume) (I made extra RSG and used 3 cups)
1 part chalk (I used 1 cup)
1 part pigment (white, english red, umber, etc.)
I found it needs more pigment, otherwise the gesso is too watery and transparent. I ended up using more than 1.5 parts.
I used Titanium because I did not want to deal with the health hazards of sanding the lead-based "Flake" white

Chalk Grounds: Directions

• Measure out the glue size solution into a metal container (I did not understand this at first - but it is to help measure correctly, since it is hard to know how much is left over in the double boiler once you have used it to coat the panels. I used a large metal mixing bowl.)
• Add the dry ingredients
• Stir well but do not whisk to prevent air-bubbles (I used a wooden spoon, worked great)
• Place container in a double-boiler bath (see my nested pot solution above)
• Apply warm mixture with a broad brush (I found it's better if the gesso is only slightly warms - when the water in the bottom pot is not full boiling, just simmering. The gesso is a bit thicker and covers more when it is only slightly warm, not hot.)
• Allow layer to dry to the touch and recoat. (I found it did not dry fast enough to re-coat within a few hours. I ended up letting it dry overnight between each layer. I also sanded between before each subsequent coat with a small handheld power sander I bought for less than $40 - so worth it!!)
• Note: When applying layers of ground, brushstrokes should be applied in one direction for every coat. Reapply subsequent layers in a perpendicular direction to the previous application. Yes this is true - otherwise deep grooves can develop which are hard to sand away.
• I ended up doing 3 coats of gesso on most panels, and 4 on a few of them. It ended up being a week-long project, spending about an hour per day.
• The gesso cools in the pot and gets quite firm overnight. I just left it in the double-boiler and re-heated the next day, it turned back into brushable paint very quickly and the texture was fine. Sometimes I added more pigment or RSG as it warmed, depending on whether it seemed too thick or too watery.

A note about my sander: I used a handheld Black and Decker sander, bought for less than $40. It had a micro-filter feature for reducing dust which worked quite well. I'm not a power-tool kind of person, but it was amazingly easy to use. Highly recommend!

Hope you find this useful! I know I'll be referring to these notes when I prep my next batch of panels, hopefully not for a good long time :)

Surface Preparation

I spend the first 15-30 minutes per painting session preparing the surface of my painting-in-progress.

Like so many other aspects of this lifelong process of learning to paint, previously I could not imagine focusing on something so mundane and technical, but I find it saves me so much time and headache later that it's worth the investment. And now I actually enjoy the sort of easy, meditative process of cleaning and preparing my surface.

First, I only paint on a dry surface that has had at least 20 hours to set for underpainting medium, and 40 hours to set for slower-drying painting medium. Painting on a gummy or tacky surface just makes a mess. (The recipes I use for painting medium and underpainting medium are in my Materials post)

Next, I use a tiny folded piece of 12oo grit sandpaper to lightly rub the surface of the completely dry layer from the previous painting session. This loosens any lint or grit that dried into the previous layer, which can then be lifted off by lightly dabbing with a small piece of masking tape.

The abrasion also gives the dry layer more "tooth" so the wet paint sticks - otherwise the oil tends to bead up.

(Abrading makes the surface a bit cloudy, and the previous rich oily areas look chalky and ugly. It's ok though, the luster comes back easily.)

Once I have a lint-free, abraded surface I use a soft filbert brush to apply a thin layer of painting medium - but only to the area I plan to work on in this session. Even a thin layer can sometimes drip or run, so I use a clean, microfiber cloth to wipe away most the oil.

This oiled surface is called a "couch" - I'm not sure why except that painting on it feels like sinking into a comfortable couch, the paint flows off the brush so easily.

To start painting, I pre-mix my puddles of values and colors on my palette with my palette knife, and then re-wash my clean brushes in Natural Turpenoid, to get rid of any dust that may have settled overnight, and also to re-wet the bristles. Then I dry the brush on a clean cloth and dip it into my painting medium.

After all that, I'm ready to start painting!

Outdoor Art Materials

I was just reading the comments in James Gourney's nice writeup for the Fellowship and realized I learned a lot about materials for outdoor painting during the trip and I thought I'd share.

Outdoor easel setup
Just about everyone was using a paint box palette mounted to a photographer's tripod for their plein air setup. (Some people preferred a light metal easel to mount their canvas and then held their palette in their hand, but there's so much to do with the non-painting hand outdoors - like swat mosquitoes - that I prefer a mounted palette).

Guerrilla Pochade Box
I started out with my 9"x12" Guerrilla box which has served me well on previous neighborhood plein air sketching but I quickly found it is too heavy and boxy for anything beyond a 10-minute hike. Considering I was climbing steep slippery rock steps most days to my waterfall site, I was really wishing for a lighter option. The plus side of the Guerrilla box is that it is extremely functional and sturdy and has tons of room for storing things. And its very cute boxy proportions draw lots of compliments. Emily Lee had the even cuter 6"x8" version and she was really happy with it, but you can see she sometimes had to use a handheld palette because the paint-mixing area is tiny.

Alla Prima Pochade
Everyone oohed and aahed over this nifty, well-designed box when it was shipped to Fellow Dorain Iten. The components are held together with magnets and the nice wood and beautiful design is eyecatching. He really liked using it, especially for the magnet that holds your palette knife while you work. The full version has awesome drawers and there is a "light" option that has separate storage compartments that attach with magnets, but even the light option still seemed a bit heavy for me.

Open Box M
Our instructors all used the "M" and after deliberating quite a while this is the option I decided to upgrade to. It's very expensive, but they offer a less expensive "kit" that includes a shoulder bag instead of the outer wooden box. However, I've personally found it very annoying to hike with a shoulder bag flopping over my arm. A backpack is the way to go.

After spending quite a bit of time on the site I finally figured out you can buy the palette/panel holder separately from everything else. I decided to order that alone, at 9"x10" and $195, and if I really feel the need I'll buy the wet panel carrier box separately later. Those two options even separately are less expensive than the kit that includes the shoulder bag - and much less expensive than the whole set which includes a wooden outer box. In the meantime, I'll use these lightweight "cocoon" wet panel carriers.

UPDATE: Lines and Colors posted a complete and detailed review of all the pochade box options available, be sure to check it out before you invest in one! It seems that Charley Parker went with the Alla Prima Pochade, it certainly looks like an amazing box. I'll come back and post and update later about how I like working with the Open Box M.

UPDATE 2: HRF Fellow Peter Sakievich posted a photo and description of his Open Box M setup on his blog.

Julian Umbrella
We all were jealous of Nick Hiltner's huge white umbrella that shielded him from rain, sun, and even more importantly... curious passersby! Several of us ended up ordering them and having them delivered directly to our location in the Catskills. Nick warned us that every part of the umbrella breaks often, but there really are no other options for white artist umbrellas we could find, and he said the manufacturer is willing to replace broken parts. Sure thing, the clamp contact has popped off, the umbrella has detached from the clamp (both luckily fixable on the spot) and after a week 3 spines had detached from the nylon. I reinforced every spine connection with duct tape so mine is not so pretty any more. All that said, it is a fantastic umbrella - it kept me dry even during one epic 3.5 hour downpour painting session. The white material casts perfect, diffused lighting on my canvas under all light conditions. And the most important feature... only the most brave passersby dare peek under the huge umbrella.

Camp Chair
I started out with the tiniest, lightest, overpriced at $20, 3-legged camp stool from REI, and in about 30 minutes realized it is miserable to sit on and has a bad habit of tipping. I "upgraded" to a folding, armless camp chair for $13 at the local hardware store. But I and everyone else who bought that one found that the seat and/or back canvas tore from the supports after a couple weeks of all-day painting sessions. The most hardcore of our group were lugging around full camp chairs with armrests which seemed like overkill to me, till I saw how nicely their umbrellas clamped to the arms, and how their turp jars nestled in the mesh cup-holders! So I might be upgrading to a fancy camp chair.

Painting Panels
I have been using wooden Art Boards in my studio and Gessoboard panels outside for a couple years now, but recently I'm finding I prefer a fine grade oil primed linen surface for outdoor painting (indoors I'll still use smooth wood for the most detail). I tried these:

Art Board oil primed linen 9"x12": $17.89
I liked the silky fine surface of these panels, but I found the damp conditions I was painting in made the panels warp forwards slightly. They will be fine once framed, but the warping was annoying on a multi-day painting.

Utrecht Master's oil primed linen 9"x12": $9.99
This panel is ok quality for a cheap price, and it's probably perfect for single-session plein air artists who like texture and thick paint. However, for multi-session painting with thin paint and more detail, this canvas has way too much texture.

New Traditions oil primed linen with gaterfoam 9"x 12": $10.17
Our instructors were using New Traditions and although I have not used them yet (just ordered my first batch) I was sold on their texture, lightweight archival gaterfoam core, and non-warping properties. And the price is right! You can choose different support materials and different finishes, but the portrait grade lead oil primed linen was my choice.

Tripod

I borrowed Dorians' tripod briefly but I loved it and hope to buy my own. The grip to move the ball head in any direction was easy and smooth and the tripod was really sturdy and even a tiny bit lighter than mine. It's the Manfrotto 190XPROB and Horizontal Grip Action Ball Head. It's expensive though, I might be waiting quite a while before I upgrade to this. There are much cheaper and lightweight tripods, and as with all things plein air the choice is between something durable/heavyweight versus something lightweight/flimsy.