Boards for mounting -
General info at http://painting.about.com/od/paintingforbeginners/a/hardboard.htm and http://www.utrechtart.com/community/comments.cfm?action=print&blogID=214
Thread about hardboards - http://forums.about.com/n/pfx/forum.aspx?nav=messages&webtag=ab-painting&msg=2604.1. And sub-threads - http://www.wetcanvas.com/Articles2/532/110/index.php
http://cool.conservation-us.org/coolaic/jaic/articles/jaic33-03-005.html – recommends against sanding Masonite
http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100058482&N=10000003+90148+503050 – mounting hardware placed on wood strips attacked to 3/5″ mdf
http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100058482&N=10000003+90148+503050 – Very useful analysis of specific brands of hardboard with winners -
1) Louisiana-Pacific’s“Premium,UntemperedHardboard,”which is the origina lAbitibi-Price product now made in th eoriginal plant by DPI .2) Masonite International’s untempered or“RegularDuron”, made in Danville, Virginia ,the original name but much-changed and refined over the year
Note – Duron does not seem to be available anymore - http://www.truegesso.com/~truegessollc773/uploads/file/Masonite%20is%20Discontinued%20-2.pdf
Golden Acrylic demo uses Medium Density Overlay (MDO), not recommended elsewhere. ["Medium Density Overlay (MDO) board is a wood panel often used in the sign making and cement forming industries. It is usually made of plywood, coated with outer layers of resin-impregnated kraft paper. Phenolic, urea, or melamine resins are the common resins used on the paper overlays. Because of the impermanent nature of the kraft papers used, MDO is not considered a suitable material for use in permanent artworks."]
http://www.utrechtart.com/community/comments.cfm?action=print&blogID=214
http://www.hudsonhighland.com/woodglossary.htm (Note this is a vendor for one brand)- High Density Fiberboard and Medium Density Fiberboard are considered the most stable of engineered wood panels. Laminated with fine wood veneers, they are often used in high quality furniture making and are prized for their warp-resistance and durability. They make excellent art panels. . Terminology can get confusing: thin HDF (THDF) of 1/4″ thickness and below is usually referred to as “thin MDF” or “TMDF” since more people are familiar with the term “MDF” than “HDF”. ”Panels of a half inch or more are generally MDF; panels of a quarter inch or less usually fall into the category of HDF, though these are generally called “thin MDF” (TMDF) since the public is more familiar with the term “MDF’ than “HDF’.”
Ampersand hardbords or gessobords are made with a wet/dry method – see http://www.ampersandart.com/tips/archivalinfo.html. Ampersand recommends using Golden’s Acrylic GAC 100 to seal panels for water-based painting and the Gamblin’s Oil Painting Ground for use with oil paints.
Blick Studio Artists’ Boards are mdf.
Jack Richeson gessoed panels are made from high density, smooth hardboard with a solid fiber core, these 1/8″ thick panels are acid free, archival and warp-resistant.
Adhesive – Golden Soft Gel recommeded in several sites
Sealing -
Ampersand info – Q. How do I seal my watercolors so I can frame without glass? Seal watercolors with several light coats of spray fixative, being careful to spray outdoors during warmer months or in a ventilated and heated area during colder times of the year. Use Krylon® Matte Finish #1311 or Krylon® UV-Resistant Clear #1309. The fixative seals the surface making it air, dirt and moisture resistant. For additional protection against scratches during transport and also ultraviolet light, follow the application of fixative with Golden® MSA UVLS or Golden® Polymer UVLS varnish – about 4 coats, brushed-on, leaves a very durable archival finish.
Golden info at http://www.goldenpaints.com/technicaldata/varnapp1.php. For brush application, the appropriate isolating medium can be made by diluting Golden Soft Gel Gloss with water (2 parts by volume Soft Gel Gloss to 1 part water). If a spray application is desired, a 2:1 mixture of Golden GAC-500 to Transparent Airbrush Extender can be applied with an airbrush, touch-up spray unit or commercial spray equipment. If varnishing water-soluble paints, including watercolor, gouache and tempera, the isolation coat must be sprayed on in very light layers to avoid solubilizing the paints, which could cause loss of distinctness of the underlying image. For acrylics and other water-based media, if the painting is composed of thin layers, waiting a day or two before applying the isolation layer, followed by another two days to a week before varnishing, is recommended.
Link also has info about thinning and applying Golden varnishes.
DB Clemons 1 - Instead of applying varnish directly to the casein paint surface, I use an isolation coat process as if I were varnishing acrylic paintings. When my finished caseins have cured for at least 4 months, I apply a gloss acrylic medium that is designed to be used as an isolation coat, such as Liquitex Varnish Medium or Golden’s Soft Gel. I can then apply a spirit varnish that is compatible with acrylics, such as Golden’s MSA, Liquitex Soluvar, or Gamblin’s GamVar.
There has been some discussion here regarding whether or not to varnish gouache paintings. I put my gouache paintings under glass and don’t varnish them. I mention it here since I believe a varnish should only be considered removable, and varnish on gouache or watercolor cannot be removed. Varnish on casein, however, if protected by an acrylic isolation coat can be safely removed, just as if it were an acrylic painting. It’s possible that egg tempera could be prepared that way also, but I’ve not thoroughly tested that.
….If you have any suggestions about how to avoid annoying brushstrokes showing up in the isolation coat—diluted soft gel medium—I’d be happy to hear them.
You might try Liquitex Gloss Medium & Varnish product instead of Soft Gel as an isolation layer. I’ve found this brushes on with better leveling than the gel and doesn’t really need diluting. You can also “polish” it on with a lint-free rag (nylon or polyester) to help avoid brushstrokes. Even though it’s “gloss” it winds up more “satin” on the dried casein so I don’t lose much of that matte softness. I follow that up with a matte varnish (MSA) and like the results. I’ve never really liked spray cans myself finding them more difficult to control.
Chuck anderson - I use masonite, but I coat front and back and sides with two thin coats of shellac, then lightly sand before I put three thin coats of “real gesso” on them. I do my underpainting for figures with detail on first with the casein paint as I find working with water thinning them down allows me to work fast and accurately. Then once my composiiton is done, I apply a coat of shiva varnish over the entire image. Then with wet 400 grit, I lightly sand and then apply my glazes and scumbles of oil paint with a coat of retouch varnish when dry. Six months I lay down a coat of damar for the final piece. If it has been sold, I make an appointment to do that for the client. Look at the artwork of the western artist Frank McCarthy. He did a lot of underpainting with casein. One must remember for a lot of the old illustrators from the 40′s, 50′s, and early 60′s, casein was the medium of choice because of the matte finish so they could photograph the illustrations with 4×5 transparency or an 8×10 to send to their advertising or magazine clients. Examine your reasons on why you like a certain medium. If you like tight work, or have problems with the drying time between glazes in oil, you might like doing the ebauche or underpainting in casein. I use only raw umber, cobalt blue and white for my underpainting. Reason being, value and shapes are my purpose. The oil palette I use is 14 colors with a full range of grays to lessen the chroma on the cadmiums and pthalo colors.
John Lovett on varnishing - http://www.johnlovett.com/preservation.htm -WAX VARNISH
Wax varnish is a matt varnish based on purified beeswax. It can be applied to Oil or Acrylic paintings and is removable with mineral turps. The varnish has a waxy consistency and is rubbed on, then buffed to the required sheen with a clean cloth. Beeswax based varnish is extremely stable and non yellowing. I also like to use bees wax varnish on large watercolor paintings to avoid using glass or acrylic glazing. The wax permanently penetrates the paper surface, deepening dark tones and enhancing colors. The Beeswax varnish (Matt Wax Varnish) I use is made by Art Spectrum here in Australia. It is simply bees wax and gum turpentine as far as I can gather, speaking to the chemist at Art Spectrum. Winsor and Newton also produce a similar product.
I have used several mounting methods. Smaller work (up to full sheet size) I have mounted to neutral pH foamcore using a heat sensitive adhesive sheet. This is an archival method and the adhesive can be released in a heat press. The downside is the cost and the fact that a framer with a vacuum heat press is required. I have mounted larger (4′x6′) paintings on a 4mm ply backing braced with pine and coated with several coats of gesso. These are fixed down with matt acrylic varnish (or you can use neutral pH PVA glue). The most difficult part of this process is getting the painting good and flat before mounting. To do this I clean the studio floor, lay the painting face down and spray the back with water. after a few minutes I then tape the painting to the floor with gummed paper tape. The painting is left to dry and shrink tight. I then cut the tape to release the painting. I have also discovered it is easier to leave a couple of inches around the outside of the painting to allow the gummed tape to be cut off rather than the time consuming sob of soaking and peeling it off.
ACRYLIC GLOSS AND MATT VARNISHES
Acrylic Varnishes are water based polymer varnishes suitable for a final finish on acrylic or water based mixed media works. They form a non yellowing, durable plastic skin that bonds permanently to the artwork. These varnishes can not be removed, but can be painted over with acrylic paint.
PARaLOID VARNISH - Acrylic polymer varnishes (e.g. Paraloid – also known as Acryloid) – Lascaux makes it, see Jerrysartarama
Paraloid varnish is a non – yellowing, turps based varnish suitable as a final varnish over dry oil or acrylic paintings. This varnish dries very quickly and can be completely removed with mineral turpentine if necessary.
Paraloid and Acrylic varnishes can be applied with a soft hake brush. Acrylic should be washed out of your brush immediately with soap and water. The parloid will need to be rinsed out in Mineral Turpentine before washing with soap and water.
http://www.apfitzpatrick.co.uk/ideas.htm – Lascaux makes a spray paraloid varnish
http://www.e-conservationline.com/content/view/568/145/ – conservation info on varnishes
Daniel smith info re Clayboard without glass – http://www.danielsmith.com/content–id-126 - I simply seal the finished watercolors with 3 to 4 coats of Ampersand’s Claybord Fixative followed by a final coat of Golden’s UVLS satin varnish.