Chapter 5

Colour and Varnish

Color and varnish in bows are less complicated than in instruments. Nonetheless it took me many years to attain a clean finish. A bad finish can spoil an attractive piece of wood. A good finish can enhance its appearance. The most attractive finish however is aged, dark wood with a full but thin shellac polish. Old wood radiates a warmth unknown in new wood. This has less to do with varnish than the surface of the wood, which changes with age. Of course, it becomes darker, but above all the transparency changes. The wood grows increasingly matt. With less light, the wood is darker. But if held under a lamp, it seems to glow from inside. The wilder the growth, the more attractive it is to look at. The flames appear so to speak because the wood fibers run in and out of the stick. According to the angles the light is mirrored differently.

I have tried everything from rabbit dung to an overdose of gamma radiation to imitate this aging proces, but with little success. The only useful agent is nitric acid. I believe this was already used in the 19th century. The advantage of nitric acid with respect to other coloring agents is that it reacts with the dye in the wood, and etches its surface a bit. In the process, the surface becomes a bit uneven, which softens the reflection. Unfortunately, the softer reflection brought about by artificial aging has a different character than natural aging, so the nitric acid treatment remains visible as an imitation. Other coloring agents penetrate the wood less deeply.

If the varnish becomes somewhat damaged, then the treatment with acid does not bring the bright orange wood directly to the fore. But nitric acid conceals its own dangers. If it is not sufficiently neutralised, then deep black spots form underneath the varnish, which look very ugly. If a bow has been handled with acid, one can see the pores are very black. This also is optically very disadvantageous.

Unfortunately, customers usually prefer dark bows to light. For the most part this is unconscious. Good, old bows are expected to be dark. There is therefore a tendency to confuse dark with good. Actually, the color of the stick has little to do with its quality. Dark wood has more coloring material in it, light has less. It is possible that light wood tends to be somewhat more porous, but also more elastic, while dark wood is denser and less resilient. But this is not always the case.

Ordinarily, pure shellac is used as varnish. All other resins leave a heavier coat on the stick, which only impedes its movement. Shellac, on the other hand, can be applied in very thin layers and, with a bit of patience and a fine abrasive, the pores can be closed. "If you want to fill the pores, use a pore filler", Roger Hargrave once told me. Since then, I tell myself the same thing everytime I have some polishing to do. Closed pores give the impression of greater compactness. But this is a purely aesthetic consideration. What matters to the sound is that there be as little varnish as possible on the bow.

On the other hand, shellac is sometimes too glassy, and gives off a hard reflection. I therefore apply a thin layer of linseed oil to the raw bow, let it soak in, then polish it. In this way, the varnish is somewhat more matt, the reflection somewhat softer. The varnish itself should not be conspicuous. What should be seen is the wood.

Synthetic varnish gives off a somewhat harder reflection of light and is often somewhat cold and whitish. On the other hand, it can be quickly applied. I nonetheless advise against it. I need at least two weeks to varnish a bow, often longer. Every layer should be allowed as much time as possible to dry. Then it should be moistened again by polishing with alcohol, and if the previous layer is not totally set, it comes off, which is exasperating.

Although polishing is not a creative activity, it is worth the trouble.

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