MITRA Forum Question Details

Let me first say that watercolors can be a very permanent medium, especially if they are created and treated in the manner that you suggest. I would bet that this is not the norm. One could also say that most oil paintings are not created and treated in an optimal manner, as well.

There are reasons why many commentators seemed to elevate oil paintings above watercolors in terms of longevity. The first is due to the nature of the paint. Historically, watercolor manufacturers were more likely to include more fugitive pigments in their watercolor line than their oil lines of paintThis was backwards thinking on the part of the art materials manufacturers. The gum Arabic binder in watercolors is very minimal and does not really surround and coat the pigments in the same way that oil or acrylic dispersion binders do. This means that the pigments receive the full force of visible and UV light. Pigments that are barely suitable in oil are outright fugitive in watercolor. The other binders are more fully covering and absorb some of that energy. The presence of a varnish creates even more of a barrier. You did address this and included only permanent pigments in your ideal description.

The paper is another source of sensitivity in watercolors, even the highest grade cotton rag paper can suffer photochemical degradation. Again, you mention the use of UV blocking glass, which would prevent this. Canvas is usually made from cellulose as well, but in traditional painting, this is covered with a ground and the paint, blocking this radiation.

Finally, the absorbent nature of a watercolor painting means that dust is easily trapped in its surface and the water-soluble nature of the medium complicates cleaning. And again, your ideal watercolor addresses this.  So if the one takes the precautions you describe, watercolor can be very permanent.

Art is only as durable as the collector's commitment to proper display and care. A watercolor needs to be correctly framed and displayed in a location that doesn't excessively expose colors to UV light. The same is true of any painting. Gallery owners have told me horror stories about valuable, important works hung in client bathrooms, over fireplaces or even on outdoor patios. Of course, the artist can't claim, "warranty void if hung in the bathroom".

Matthew, the same thing can be seen on paintings hung on exterior walls (those that have the outdoors on the other side as compared with interior walls). The movement of moisture through the wall has a major impact on preservation. I have images of a pair of pendant portraits from the 19th century that were painted at the same time and with the exact same materials and techniques. The one hung on the interior wall is in very good condition while the one hung on the exterior wall is flaking and in a poor state of preservation.