Rubens on using white

“Begin… by painting your shadows thinly; be careful not to let white insinuate into them; it is the poison of a picture except in the lights; if white be once allowed to dull the perfect transparency and golden warmth of your shadow, your colouring will no longer be glowing, but heavy and grey…”
“The case is different in regard to the light; in them the colors may be loaded as much as may be thought requisite. They have substance; it is necessary, however, to keep them pure.”

-Peter Paul Rubens, from Eastlake

Classical Technique: The Frottis

Madame_Récamier_by_Jacques-Louis_DavidThis unfinished painting, “Madame Récamier” by Jacques-Louis David exhibits the initial rubbed-in image called the frottis.

The frotté (“rubbed”) technique involves a thin layer of oil color diluted with thinner, applied with vigorous brush work. While the palette is largely composed of earth colors, the image is actually worked up in a relatively full palette even at this early stage. This approach establishes a lean (low oil), smooth underpainting that supports subsequent layering.

Bright (short flat) natural bristle brushes work well for For the frotté technique (though David’s work precedes the development of metal ferrule flat brushes).–Brights-MP28322-i1005897.utrecht

Do I really have to wait 6 months to varnish my painting?

varnishingHow long to wait before varnishing depends on several factors: type of paint, specific pigments and mediums used, thickness of application, type of ground/support, and ambient temperature/humidity in storage. Oil paints cure slowly over months, while acrylics dry very quickly by evaporation. Even with acrylics, however, thick applications can remain soft internally for weeks. Some oil colors dry more slowly than others, so a single passage may remain soft while fast drying areas are fully dry. Paintings stored in cold, humid conditions may dry more slowly than those stored in warm, dry environments.

Oil paintings dry to the touch can receive a coat of Retouch Varnish or light application of synthetic picture varnish. Retouch Varnish restores luster and imparts even gloss, deepening colors while it protects the paint film.

It’s generally best to wait 6-12 months depending on paint thickness, or until paint has formed a firm solid before applying a heavy final varnish. (The 6-12 months “rule” dates at least as far back as A.P. Laurie’s “The Painter’s Methods and Materials”, 1926, at a time when heavy resin-oil varnishes were still in common use.)

If damar retouch has been applied, it can either be removed for re-coating or full-strength damar can be applied over top. (For best results do not top-coat retouch damar with a synthetic varnish.) A light single coat of synthetic varnish can be top-coated later with the same product.

Varnishing early isn’t likely to retard drying by oxygen starvation (modern grounds remain permeable from the back), but varnishing still-soft paintings can result in an imperfect top coat with irregular texture or bloom beneath the varnish. Of course, paintings wet to the touch should not be varnished at all- varnish can intermix with colors, making removal without damage to the art nearly impossible.

Acrylic paintings can be varnished as soon as they are thoroughly touch-dry and solid through the entire film. For best results, no residual moisture should remain.

Proper picture varnish should remain optically clear, flexible and neutral in color and should be reversible to facilitate future cleaning and conservation. Think of varnish as analogous to glass over works on paper: distinct and separate from the artwork, replaceable and unobtrusive. Synthetic solvent-borne varnishes like Gloss Picture Spray Varnish or Gloss Oil Varnish are good options for both oils and acrylics.

Free download: “The Painter’s Methods and Materials”, A.P. Laurie, 1926

Retouch Varnish:

Synthetic Spray Varnish:–Archival–Gloss-MP68798-i1003774.utrecht

Varnish Brushes:

House Paint vs. Artists’ Colors?

house paintOne of the most frequently asked questions in art materials retail is whether house paint can be used as a substitute for artists’ acrylics and gesso. The short answer is no, house paint does not generally perform as well as artists’ acrylics in terms of durability, lightfastness and appearance. Artists’ acrylics are similar to architectural paints, but there are some important differences. House paint is designed for different performance standards and applications than artists’ paints; this does not mean architectural coatings are inferior to artists’ paints, but they don’t always satisfy every requirement in the artist’s studio.

Artists’ pigments are tested for lightfastness ranging from average to excellent. (Colors of poor lightfastness are not used in professional-grade paints.) Not all colors are equally resistant to fading, but most used in professional quality artists’ paints are highly permanent, able to endure many years of normal light exposure without perceptible color change.

Pigments used in house paints are selected for mixing designer colors, usually with lots of white. Tints are mostly based on synthetic-organic (man-made) colors that need to last about 10 years without significant fading. That’s not to say that they may not last longer, but since walls are typically painted every few years, most consumers don’t expect or require better performance.

Vehicles and binders used in house paints vary from one manufacturer to another, but usually the term “latex” or “acrylic latex” is used to describe the polymer base. There’s no natural latex rubber in house paint- “latex” is a generic term for all sorts of water-borne polymer emulsion/dispersions.

Most manufacturers will not disclose exactly what polymers are used in their products, and not all synthetic emulsions are equally good for artistic painting. Many house paints are made using a more economical copolymer base that combines different resins, like styrenated acrylic (as opposed to pure acrylic). Styrene is more prone to yellowing than pure acrylic, so house paint color mixtures may not remain as originally mixed and a wall primer ground may not remain as brilliant or neutral as when it was freshly applied. Professional-grade acrylic paints, mediums and primers are made using top-quality 100% acrylic polymer base with stable, neutral color and excellent flexibility.

House paints sold outside the US are not always based on acrylic- many are made using a PVA base. Not all PVA is durable to archival standards; some types can yellow or become brittle from UV exposure. Also, since PVA is less flexible than acrylic, plasticizers are added to make the dry film more pliable. These compounds may not remain permanently in the paint, however, so a PVA house paint film may become more brittle as it ages.

In addition to pigment and vehicle, house paint contains a much higher volume of bulk materials like calcium carbonate (“marbledust”) compared to artists’ paints, and may include substances like talc not normally used in art supplies. These fillers are not as opaque or brilliant as white pigment so house paints don’t offer the same coverage and hiding power as artists’ paints. This is not usually an issue when covering a well-primed wall, but in complex layering on canvas the difference in performance is apparent. Also, fillers can render the dry paint film less flexible; heavy applications may crack.

Calcium carbonate is used in professional artists’ paints to provide body and workability, but bulk agents should never be used in a high enough proportion to compromise flexibility or affect color.