Creative Techniques: What Are Supports
What are supports? Supports are the structures on which you apply your paint or the structure on which the paint and ground layers of a painting adhere. These structures can be rigid or flexible. Flexible structures usually consist of paper or canvas. In this newsletter I’d like to talk about alternative rigid surfaces such as woods, foam boards, and Plexiglas® surfaces. The main advantages of using a rigid support includes less instances of cracking with oil paints, less sagging when using heavier acrylic gels and a less brittle surface for casein or egg tempera applications.
Woods come in two main types: softwoods and hardwoods. Hardwoods are more durable and resistant to wood rot and are usually the chosen woods for artists’ panels. Golden Artist Colors would consider a good quality plywood more stable than Hardboard.
Recommended panel materials could include, MDO (Medium density overlay aka as sign painter’s board) and, Ampersand. It may be hard to find a Baltic Birch door skin but it is a great type to use “as if” it were “plywood”.
For a low cost and readily available option try door skin. Door skin (aka a hollow core door or mixed hardwood ply), another alternative surface, is used by some artists requiring a lightweight yet rigid surface. This thin veneered plywood has wood edges and a corrugated cardboard center which can be prone to glue degradation and needs to be primed as well. If choosing this surface look for the best quality you can find such as a Hardwood or Birch surface.
Plywood is often used by artists and is generally made from poplar or birch timbers. Ray Smith from the Artists’ Handbook states that “the best plywood is W.B.P. (Weather and Boil Proof).
Blockboard, often used in shelving material and resembles a butcher’s block with a veneer on top, can be used but the quality of the blockboard varies so warping and durability could be a possible concern.
Chipboard, often used in furniture making and flooring, is a dense material made of compressed wood chips but is heavy and hard to maneuver although they can be used for artists’ support. Golden Artist Colors does not recommend chipboard as an artist support as it has similar issues as MDF or HDF (Medium and High Density Fiberboard).
More attractive to artists these days are what are known as composite panels. “They are made from wood which is reduced to a pulp and then reconstituted with various synthetic resin-type adhesives. These panels are known as Hardboard (aka as Masonite®), Medium Density Fiberboard or MDF, and Ampersand boards. Recommended boards are the Baltic Birch plywood (even though Baltic Birch is not a composite panel as defined above) and Ampersand boards.
Hardboards have high levels of impurities (lignins and tannins) which can create a problem when working with acrylic gels or large amounts of mediums known as Support Induced Discoloration. This situation arises as acrylics, a water-based medium, do contain water in their formulations. The longer an acrylic takes to dry (especially gels) the more potential for leeching the impurities (lignins and tannins) from the hardboard and having these impurities migrate to the surface of your support. If you do use boards it is important for you to protect yourself from this potential pitfall by doing the following: degrease the smooth side only using Isopropyl alcohol, then putting 2 coats of GAC 100 (from Golden Artist Colors), and 2 to 3 coats of Gesso.
MDF boards, often used for “false wall mural work”, are similar to untempered masonite but can be problematic if wet or dropped. The edges are more absorbent than their surface and should be well sealed especially if working with any water-based products. The “A” grade are light and rigid and have some water resistance according to Ray Smith.
A newer and improved hardboard can be bought at Ampersand. According to their website, tempered hardboard was made by immersing the panels in tung or linseed oil to harden them but the oily residue caused adhesion problems and untempered boards easily frayed and chipped. Ampersand discovered that the species of wood utilized, additives and manufacturing techniques affected how masonite behaved. They chose a Wet/Dry process whereby pulverized wood fibers bathed in water (an internal bond is created using the natural resins in the wood) then a dryer is used to remove water from the fibers and then pressed between two plates. Doing this process removes the tannins and lignin’s that can cause discoloration. Their tree of choice is the Aspen tree that contain more of a neutral Ph. Ampersand claims that todays tempered and untempered hardboards do not cause adhesion problems.
The company recommends the tempered hardboard as it resists warping, the edges won’t fray and a better seal is created with oil and acrylic primers. Ampersand seals and applies acid-free grounds which creates a barrier to harmful seepage and insures that they will not interact with the grounds or the paint. Their boards are considered High Water Resistant which may or may not be comparable to Weather and Boil plywood.
Sintra, which is made of expanded PVC foam is another interesting support for painting. It is a lightweight yet rigid board which can also be used for archival framing applications, signage and direct digital printing. It is easily formed into any imaginable shape including curves (using wood and foam board fabrication techniques). These foam boards are also available in many different thicknesses, colors and possess a low gloss matte finish. PVC stands for Polyvinyl chloride.
All wood surfaces should be sealed using GAC 100 from Golden Artist Colors for any water-based products to reduce lignins and tannins from affecting the surface. If using oil paints Ampersand recommends using Gamblin’s Oil Painting Ground. Golden Artist Colors and Ampersand both have comprehensive and excellent websites that can help you determine what supports may best suit your needs and how best to treat your surface.
Generally, a good rule of thumb to cover most wood or wood fiber surfaces is to apply 2 coats or more of GAC 100 (which acts as a buffer for particle transmigration) and 2 to 3 coats of Gesso.
Plexiglass sheeting (make certain it is an acrylic and not a polycarbonate) needs to be cleaned with a mild detergent and you can then work directly on to the surface adding GAC 200 for added adhesion on the slick surface. Another way of preparing this support is to do a pre-treatment of the surface with GAC 200 and GAC 500 in a 3:1 proportion.
Sources: The Artist’s Handbook, Golden Artist Colors, Ampersand, SintraBack