Summer

A recent work in progress, this was my first big project on gessoed oak panel. I braved the sauna-like July weather, and ventured out to a brand new location. For this painting, I'm still relying on my full palette of hand-made pigments.

This picture started off with a lot of promise. Then I started having a series of "off" days, and the picture suffered as a result. Especially in the foreground. I'm going to set this one aside for awhile and return to it.

Making Panels Part II

Once the panels have been cut to final shape, they can be smoothed and prepared for gesso. I usually sand the panels with a moderate grit sandpaper, making sure that the edges are smooth.

The moisture in real gesso sometimes causes the wood grain to swell, the amount depending on the species. Because gesso is rigid, this can lead to cracking later on. To prevent this, the panels are rubbed down with alcohol, which raises the grain of the wood, Once dry the panels are given a final sanding.

Now I can start coating the panels.















First, the panel was given a few coats of size, made from hide glue. I used rabbit skin glue for this task. The glue was added to water in the correct ratio by weight, and allowed to sit over night. As you can see, it swelled considerably.

The glue was heated until all of the pellets have broken down into liquid. I continue to only use warm water in a sink to heat my glue, a glue pot being overkill. Once liquified, the glue is passed through a sieve, and its ready to be used.

The panels were given several coats of size, front back, and on the sides. The following day, gesso was applied

Real gesso is a mixture of hide glue and an inert white pigment, that is porous. The ground is absorbent, so it readily bonds the layers of paint to the panel, while at the same time isolating the two. There is more than one suitable choice for this material. I have chosen to use calcium carbonate, in the form of chalk. Chalk from the Champagne region of France is one of the most pure natural chalks that can be found.

I saved the leftover glue from sizing my panels, as a base for my gesso. The correct mixture involves adding chalk at 1.5 times this volume of glue.

First the glue must be made hot, then the chalk was slowly added. I stirred gently, taking care not to do so too vigorously. Stirring gesso too enthusiastically will introduce tiny air bubbles into the mixture. Once these bubbles are on the panel, they cannot be filled or removed, no matter how many additional coats of gesso are applied. Once all of the gesso was been added to the glue, it was allowed to soak in for ten minutes.














The panel are given a coat on each side, to seal them effectively. Its important to try to make the coats as even as possible. Gesso puts tension on the wood, and uneven tension could lead to problems later on. An equal number of coats front and back should minimize this stress.

After a coating of gesso is applied, the board was put aside to dry. This lasted twenty minutes to an hour. Then the next coat was be applied and so on. Coats should always be applied in overlapping passes, i.e. a coat across the width of the board should be followed by a lengthwise coat. Five to ten coats should be sufficient to get a good surface. It is possible to get carried away, and produce a beautifully smooth surface. That would require many extra coats, followed by lots of sanding.

Once all of the coats are applied and the panel is dry, there is one last step to prepare the panel. Raw gesso is very hard on brushes, and is too absorbent for oil paints. A final isolating layer needs to be applied to reduce this tendency. A thin layer of glue size is sufficient. Each panel should be given a week or two to dry, and then is ready to be used.

Making Panels

Over the next few weeks I plan on making an assortment of panels for painting. As discussed in my post on painting supports, panels have a variety of pros and cons. I have come to the conclusion that overall they are the best kind of support for works of small to moderate size. For larger works, I will still rely on canvas.

I recently located some furniture-grade, quarter sawn oak boards. These boards were kiln-dried, but had been aged 4-5 years. Oak was the most popular wood for use as a painting support in Northern Europe. It is a fine wood for use as a painting support, as a visit to any museum containing these pictures will demonstrate.












The boards were first cut to the right shape and size. Any final sanding or planing could be done at this time.












A larger panel necessitated joining more than one board together. The lap joint I cut into the boards is a traditional and effective method of joinery. Both halves are from the same board, but have been flipped so that if warpage does occur, there should be a counter effect.

More about Painting Supports

Rigid panels have been used as painting supports for millennia, and are an excellent alternative to canvas. There are oil paintings done on panel that are still in excellent condition after 500 years. The greatest flaw of canvas is that it is not rigid, and the condition of many older paintings have suffered because of this fact.

Panels can be made to have a wonderfully smooth surface that is excellent for painting in detail. For those that desire a more textured surface, canvas can be glued to the panel, for the benefits of both.

A lot of materials are suitable for use as painting supports. I have organized some of the more popular choices into groups.


WOOD


Wood is one of the oldest painting supports, having proven itself in use over thousands of years. Many different species are suitable. Historically, Poplar was a common choice in Southern Europe, Oak in the north.

Wood has some drawbacks. It can rot, and be attacked by pests. Wood is not always dimensionally stable, and can warp. The susceptibility to all of these problems will vary by species.

With the right preparation, these issues can be minimized. Wood should be aged properly to ensure that it is dry and acclimated to its environment. This process used to take up to ten years. Nowadays, most woods are kiln dried, which does not always ensure a wood is completely dry. I try to work around this issue by using old or reclaimed wood.

Panels made from wood were usually braced in some manner to make them stronger and to resist warping. There were a variety of ways of doing so. Ongoing research by conservators suggests that these methods may do more harm than good. Braces can't stop a panel from eventually warping, and in the process put extra stress on the wood.

I have chosen not to brace my panels. The method I have adopted instead is to size and gesso the panel equally on both sides to ensure it is sealed. This is based on historical recommendations and backed by modern research. I use wood that is as close to quarter sawn as possible. This is wood that is cut down the center, so that the grain runs parallel along its length, making it more likely to be warp resistant.

Plywood is made by gluing many thin sheets of wood together, in alternating layers. This makes a solid sheet that should be stronger and more warp-resistant than the same wood in regular form.

Plywood suffers from drawbacks unique to its construction. Boards can warp, plies can de-laminate, and the glues used to hold plies together can leach out and cause damage to the paint. The quality and price of modern plywoods is all over the map. I've had a lot of issues trying to use plywood as a painting surface with traditional gesso. Soon after making them, my panels developed micro-fine cracks, caused by the wood grain swelling from moisture. This is fairly common, from what I understand. I would suggest doing your own tests and experimenting, before using plywood on anything you consider important.


ENGINEERED WOOD PRODUCTS


Products that have been manufactured using ingredients derived from wood. Their benefit is that they are more dimensionally stable than wood, should resist warping, are widely available, and inexpensive.

Hardboard, aka Masonite, is a type of dense fiberboard. It is made from wood fibers that have been compressed under extreme pressure, until they are bound together. No glue is used in this process. Hardboard is strong, dense, and has no grain.

Hardboard panels have been in use long enough to get an idea of their longevity, with mixed results. Some vintage paintings are in good shape, while others have not fared well. "Tempered" hardboard, has been coated with oil to make it more weather resistant. There are cases where this has reportedly leached into the paint surface and ruined it, so tempered products should probably be avoided.

The majority of premade "archival" artists panels are made from some kind of hardboard. Without knowing specifics about how a panel is made, I would think twice about using them for anything but smaller, more informal works.

MDF or Medium Density Fiberboard is made from ground wood fibers bound together by a glue or resin. It is weaker and less dense than hardboard. The resin used to bind the wood fibers poses a health risk as it is usually formaldehyde-based. Protection should be worn when working with MDF.

MDF is a relatively new material, so long-term permanence is still open to debate. How long the resins that hold the material together will last is a big concern. MDF is relatively soft, so it can be dented easily, especially around the edges. It can also swell if exposed to water. I would recommend sealing MDF on all sides before use.


METAL


Metal has been used as a panel support on a limited basis for centuries. Rembrandt used copper for some of his smaller works, and these are still in excellent condition. Provided that there is a sufficient bond between the paint and metal, it is in many ways the ideal surface. Metal is rigid, stable, and expands and contracts relatively little. The drawbacks include the added weight and expense of many metals such as copper, and the possibility for corrosion unless sealed from the atmosphere.