Varnish has been deemed the holy grail of violin making.
I am writing this recollection of my approach and practise as much for my own benefit as for a customer, who might want to look behind the scenes. For most luthiers there is never an end to refining and revising “their”varnishing process.
So many paradoxical features are desired in varnish, which confuse and disorient the novice: We dislike a uniform surface without texture, but neither to we want a blotchy and inconsistent varnishing job. We love a silky shine, but not a plastic like gloss. We require transparency to the wood, but not an anemic colour. The ideal colour is not brown, but please neither fire engine red. In fact we want many colours all at once. The surface character should neither be a hard and heavy carapace, nor can it be soft and fragile ….
Varnish carries the myth of forgotten secrets. Undoubtedly the look reflects the maker’s practise and artistic control.
It is interesting how varnish emphasizes rather than hides craftsmanship. Faint tool marks show up sometimes in the varnishing, and if they show a fluid process, add to the beauty. Most makers finish the white wood whetting the grain and using scrapers and horsetail to cut the raised grain, rather than sandpaper, which tears the fibres.
Modern eyes dislike the look of red varnish on white wood. Red or orange feel brash on new wood and cold to us. Ironically the old masters might not have preferred the slowly yellowing background and instead liked the intense, clear new colour coating.
The aesthetics of the background are as important as the varnish . We need to achieve the tanning as well as a sealer ground coat keep the coloured varnish from seeping into the wood and staining it.
The “spark gap” is very effective for tanning, works best in a damp, warm atmosphere, but needs a guarded set up to be safe.
Koen Padding’s long years of research on classic instrument coatings resulted in varnishes and ground treatments, such as the “Imprematura Dorata”solution, sold under the “Magister” label.
It was a precious tincture widely used, alas no longer here for us. It required magically little time in UV light to achieve a golden ground.
Friends and fellow luthiers of Koen Padding compiled this book, including Koen’s articles and recalled conversations on violin varnish. A look around Koen’s workshop reveals research in progress, workstations and features the materials Koen worked with.
The chemical stains Koen likely employed to produce the “Imprematura Dorata” don’t cause the dreaded negative stain on spruce. Time and experiments with combinations of said chemicals lead to a workable solution, not in my case equal to the Magister product however.
Chrapiewicz ground, a saponified linseed oil/potassium silicate emulsion fulfills both the tanning and the ground coat requirements, but like many good things requires weeks of drying and darkening time. In my experience the emulsion does not store.
I have used gesso grounds, ( this with the idea of case hardening the shell), varnish pastes with kaolin, or simple clear resin coats to seal the tanned wood. The commercial “Liquin” does the sealing for my workshop series violins.
Varnish finally is the resinous top layer, usually build up in several applications. It consists of a resin dissolved in drying oil and or solvent. It’s function is to show off the instrument as well as protecting it from moisture and sweat. Pigments – or in the case of spirit varnish – tinctures are added for colouration.
Varnish does have a dampening and melding effect on the tone- beneficial to a point, but you don’t want a straight jacket.
Pine resin, Sandarac, Mastic, Elemi, Aloe, Copal, Venetian turpentine, various Shellacs, Benzoe, gums, colouring agents, a string of chemicals, some relatively inert, others reactive- even nefarious flooded our varnishing cabinets. There were too many materials to come to terms with.
At the Welsh School of Violin Making we learned to cook “Fulton’s”, a polymerized Venetian turpentine (larch resin) varnish. It was a good coating, perhaps a little anemic without pigments and quite glossy.
Students inclined to experimentation heard about adding ferric chloride to manipulate the colour towards a nice fox fur orange. This looked beautiful initially, but deteriorated with an unsightly craquelure over the years
Just for the record :this instrument’s sound is superior. Moreover a few years ago we met a similar looking instrument made by Joseph Kun, the Ottawa luthier who designed the Kun shoulder rest. Upon Joseph’s request, Greg had recommended this treatment. Joseph K. ‘s violin sounds equally convincing and is priced by the player, but we don’t advocate adding ferric chloride to varnish anymore.
We had other bad experiences, for example with colophony ( spruce resin varnishes) turning grass green. This might have been a reaction between pigments and the acidity of the varnish. Our Michelman’s colophony varnish darkened and rolled off. Again this could have been entirely due to a faulty procedure and application rather than the actual recipes, but we did become somewhat discouraged.
We needed method, consistency and fewer ingredients. The classic varnish probably came from the apothecary and we to needed an experienced alchemist.
In around 1988 we bought Gaery Baese’s book “Classic Italian violin Varnish”, an extensive ,organized and well presented research into the dizzying array of classic recipe sources and historic references. It is a pleasurable book to own with colour plates, material portraits and a comprehensive list of relevant historical sources. Baese deals with provenance of ingredients, terminology, trade history, production and application of varnish.
We started to boil varnish using sun thickened linseed oil, fused amber ( instead of Greek pitch) and mastic according to a recipe from the Marciana manuscript, a 16th century collection featured in G.Baese’s book.
The expensive fossil amber was probably less widely used than Aleppo pine ( Greek pitch), larch resin, Sandarac and other recent resins, but we were attracted to the stability and inherent darkness the resulting varnish.
According to need we moderated the “cut ” (proportion of oil) depending on wether the varnish was to be used as a first or last coat. We reduced the mastic content, as it seemed soft and took imprints. However it would be more appropriate to call Mastic, the exudation from the pistachio bush, a plasticizer. It was used since antiquity for mouth hygiene as a chewing gum. We also started using bubbled and boiled Walnut oil for the top coat as it dries with a matter silkier surface.
The somewhat disagreeable part of the varnish production is the fusing of the amber as the fossil resin would not otherwise dissolve in the boiling oil. This operation takes up to 3 hours heating at a temperature between 250C and 300C while releasing toxic fumes. ( succinic acid).
We have to restock our “amber cake “supply about every 5 years using amber dust left over from the jewellery industry. For many years we had no immediate neighbours. Now with only one wild overgrown lot left to the South, we have to be considerate with timing and wind direction.
You can imagine the disappointment when we discovered that a shipment of amber dust was no longer pure. Was it adulterated with plastic as amber had become more and more popular? The contamination resulted in an unusable fused amber. Now we use amber fragments too small for jewelry and crush them in a mortar , or place them into a bag and smash them with a hammer before fusing.
We also prepare a good quantity of sun thickened walnut and linseed oil to have on hand. This will be boiled and combined with the now easily crushed fused resin and carefully heated until the “firm pill”, the polymerized stage is reached. The original recipe contains no thinner and needs to be filtered while warm.
Left without amber cakes for a season in 2017 we discovered TedN.’s oil varnish suggestion on Maestronet. It is made from pulverized FF grade pine resin combined with umber earth colour in linseed oil. Note the different set up . A baby jar containing the boiled linseed oil, crushed resin and umber earth is set into a tin filled with sand on the hot plate. The mixture reaches 300C within 30 minutes and foams strongly before reaching the firm pill stage. The relatively short and less energy intensive process results in a dark, pliable, stable varnish. Thank you Ted N!
I understand and respect other luthier’s fascination with antiquing. The various textures and colour contrasts add interest. The best copyists are starting with a perfectly evenly applied varnish and put on decades of wear via imagination and many risky operations.
However the aspect of rushing time in our inflationary epoch keeps me from pursuing the antiquing practice. My aim is for the instrument to look warm, alive and age well. The “tampon” method, i.e. using the hand to apply the pigmented layer, produces a flow of accumulation intensity, which I hope lends a lively shimmer to the surface.
I have played my first Canadian cello now for 30 years. The varnish composition comprises amber and mastic at a 1:1 ratio. There are textile imprints from hot summer days in an extra padded cloth case and I need to stay on top of the rosin accumulation on the belly. Amazingly I am able to rub out the cloth imprints by means of a cloth and elbow grease without loosing the colour. ( Not to be done on a sticky, hot summer day). The initial chestnut brown colour ( purple alizarin lake) is mostly intact. There is a bit of wear on the high contact areas and a tiny bit of natural craquelure on the base of the scroll . Mastic also convinces with a silky soft sheen.