Coating system I
Below is an explanation of the Byzantine finishing system and its use when creating classical violin coatings.
More background information to this topic is given in the article “A rational look at the classical Italian coatings”
on the Publications page of this site.
The term "classical varnish" is a misleading generalisation and it has caused many researchers to focus primarily
on varnish when attempting to emulate what is in fact a multi layered coating. A coating is a system of layers.
Our perception of a transparent varnish is created only in part by the varnish itself ! Because all of the layers
that cover violin family instruments are transparent, the first few layers of wood structure and any layer that may
have been applied to this subsequently, all influence the appearance of the actual varnish on top.
All of these possible layers together are called a coating and only a part of this coating may actually be varnish.
From a purely technological point of view, there is little to justify the grouping together of varnishes as divers as
those of e.g. Andrea Amati and Nicolo Gagliano under the same heading "classical varnish"
But the fact remains that classical coatings share an almost indefinable optical attraction. In our opinion this
is mainly the result of very similar products being used for the first three steps of the coating. During the entire
classical period the last two steps, the actual painting and/or varnishing, show much more variation.
Just like the system that you use to make a violin, influences how the instrument will look and function, the
system that is used to create a coating will influence the appearance and (long term) performance of that coating.
Only a proper matching between the various layers in this system and the materials used for each layer can
cause the qualities of a coating to transcend the sum of it’s components.
If anything; this was the "secret" on which the success of classical coatings (as opposed to varnishes) is based.
We believe that an age old communal finishing system was the theoretical basis for classical violin makers when
it came to varnishing. Because this system had been in use for centuries to decorate all kinds of objects, it was
firmly imbedded in the cultural heritage of Barock artists and craftsmen. For woodworkers this made it the most
logical - perhaps even an unquestioned - method to follow when it came to varnishing. Because in the case of violin
family instruments the carrier (the instruments wood) played a crucial role in the appearance of the finished work, the main difference to decorative paintings was that the total coating had to be transparent.
* The Byzantine finishing system *
In principle this consists of five steps, the purposes of which are:
1. Priming
To prepare the substrate, so that it will accept the coating and to improve specific substrate qualities.
The classical violin primer gave the wood its golden colour, but this was a variable side effect.
The main reason to use primers like our Imprimatura Dorata would have been to stabilise and harden the wood,
protect the fibre against wear and dirt, increase its translucency, and to maximise the amount of reflected light.
2. Sealing
To take the “hunger” out of the substrate, so that the ground will not sink into it excessively.
ln classical violin coatings the sealer could also have been used to give the wood fibre extra protection.
A sealer should never perform the role of a ground. In classical coatings it is the ground that fills the pores of
the wood, not the sealer. If used, a sealer should be present as an almost unnoticeable layer only.
Whereas step 1,3,4 and/or 5 are always present in classical coatings, a sealer may not be present in all cases.
3. Grounding
To provide a stable and even foundation for the painting.
Even should not only be interpreted as in smooth, but also as in even in it’s acceptance of paint or varnish.
The key and central role in the Byzantine system is performed by this third step, the ground. And it is this layer
that invariably shows up as an ivory white layer when classical instruments are examined under black light blue.
The classical ground is the transparent version of what in painting is referred to as the “gesso”
In a very real sense it must have been understood to be the foundation that gives stability to the entire coating !
Because it has been shown that classical grounds hold silicate filler material and they are transparent, they must
be based on a drying oil (varnish) Many filler materials could be considered as candidates. However; transparency
is only a specific requirement for classical coatings whilst the original purpose and essence of a ground was to
provide stability and evenness. This narrows down the candidature for most purposeful filler in an oil medium considerably, making an amorpheous silicate like pumice powder the best technical and historical choice.
4. Painting
To apply colour or an image. If a varnish holds particle matter it is technically speaking a paint.
Our habit of talking about classical coatings as varnishes, causes us to think about and classify them as such.
This can limit our willingness to consider anything that is not runny and brushable. Thinking about the execution
of at least this coloured part of the coating as painting, will expand your possibilities to create variation.
Recreating the intense and luminous colours of especially some later Cremonese instruments and doing this
in as thin a layer as is sometimes evident, almost certainly required the use of very highly pigmented “paints“.
So in reality some of the most striking classical violins are not only varnished, but first painted and than varnished.
Applying not only these paints, but all strongly coloured oil varnishes in even layers over a relatively large surface
would have been (and still is) easier to accomplish by pad printing method than with a brush. At the start of the
classical period this method had already been used for centuries to execute the final varnishing of paintings.
In the case of tempera paintings this final varnish layer was usually a high quality Vernice Liquida Comune.
5. Varnishing
To protect the painting from outside influences and to even out differences in surface texture.
Early paintings were usually made by using a variety of techniques and materials in one painting and different
pigments often required the use of different media. This made “evening out” a very important part of the process.
When applying non pigmented coloured varnishes, overvarnishing with a clear varnish is usually superfluous and
really only usefull if you want to cut back the surface of the varnish substantially to get a super smooth finish.
* Standard varnishing procedure *
In the information sheets that accompany our products, we suggest many variations on the Byzantine system.
This could easily have the effect of marginalizing the importance of the system as the central framework for all
of these variations. In the Byzantine system (or any other coating system) the quality of the finished coating is
related to every step of the system and the way in which these are executed.
Variations on and shortcuts through this system can be made, but in my experience these are much more
successful and educative if these are based on a firm understanding of the system.
Using this system and the information that accompanies our products, a good working sequence to get familiar
with before you start improvising would be the following:
0.
- Finish the instrument in the white with scrapers and burnish the wood with shaving grass.
In principle this could already be seen as part of the priming process.
1. Priming
- Apply 2 coats of Imprimatura Dorata Primer to the pine and 3 coats to the maple.
- Expose the instrument to UV light in a warm, sunny place or a drying cabinet (for about 12 hours)
2. Sealing
- Apply 1 coat of Imprimatura Dorata Sealer to the entire instrument.
- Leave the instrument in a warm, airy environment (outdoors in a semi shaded area) for another few days.
3. Grounding
- Grind 20 - 40 % pumice powder into one of our clear varnishes.10 grams of varnish makes 12 -14 grams of ground.
- Apply two coats.
This ground can also be rubbed into the wood only, three or more coats will become clearly visible as an
uncoloured layer underneath the coloured varnish.
4. Painting
- Use a straight coloured varnish, or grind extra pigments into this and apply your colour by Pad printing method.
With our Vernice Liquida type of varnishes, this method can be used as long as the varnish still responds.
Linea Cremonese varnishes are best pad printed about 15 min after application.
The ratio of pigment to varnish can vary. 1 : 4 (by weight) is a high average.
Our Doratura paints can save you the laborious grinding. They can be mixed into all of our varnishes.
If you want to use a solvent, use old fashioned (non perfumated) petroleum but use it very sparingly.
A few percent will already decrease the viscosity of the paint noticeably. In some countries this mineral oil
distillate is known as paraffin or kerosene lamp oil. White spirit (mineral spirit) is a safe substitute but a little
faster evaporating. If you are using a brush and find that the varnish doesn’t work very well, consider changing
the brush before you start to change the varnish.
- Our I.D. Sealer can be useful for thinning down varnishes to brushing viscosity, without altering their tack ratio.
- In case you are using only a low concentration of pigments, you can decide to skip the next step.
- If you are using a straight coloured varnish you have already performed it and have skipped the painting.
5. Varnishing
- Finish the process with 1-2 coats of either a clear varnish or an unpigmented coloured varnish.
If you want to cut down the varnish substantially with an abrasive, a clear varnish may be preferable.
Leave the dried varnish to mature for about 2 weeks with mild sunshine or equivalent drying cabinet time.
Hang the instrument in a warm, dry and airy environment - preferably outside - in between sunshine sessions.
- Only now do your final polishing, after which you can start the fitting up.
Polishing can be done with ever finer abrasives until you reach a fineness that actually leaves a shine.
You can also change over to French polishing (with only oil and alcohol) at some stage during this process.
French polishing a Vernice Liquida type oil varnish becomes easier as the varnish film matures.
- Alternatively; one last strongly diluted layer of varnish can be applied with a soft brush.
Give this coat another few days to dry!
Unlike violinmaking which can benefit from a certain amount of panache in its execution and an "ad lib"
attitude towards the original plans, varnishing should be approached methodically and with patience.
There is an old rule of thumb which says that ”the longer you take for your varnishing, the longer it will last”
This of coarse has it’s practical limitations, but in general varnishes - and specifically oil varnishes - are not
improved by haste. If you are really in a hurry, think about how you can cut down on the number of coats
(preferably before you start varnishing) rather than cutting on the drying times.
Alternatively you can send your customer your excuses for the bad varnishing weather, it's been done before.
We all have our own history of struggle with varnishes. What we struggle with becomes part of us. It is therefore
unavoidable that a sense of personal integrity surrounds the coatings that we apply to our white instruments.
Understandably we are reluctant to change our methods or materials unless we have worked out these changes
ourselves. At the same time though “our” white instrument first entered the workshop as wood from so and so.
Similarly; if we receive new information and work with it, there will unavoidably come a point where we can and
will regard it as our own. Knowledge about a certain subject does not grow out of only gathering 2nd and 3rd
hand information, but out of personal struggle with that information.
* The Pad printing method *
Historical Vernice Liquida type varnishes were usually formulated to be applied by “pad printing” method. Although obscured by the passage of time, this was a common method for applying oil varnishes until the late 17th century. Pad printing (or stamping) functions on the same principles as a “modern” paint roller, the use of which was in principle already described by Cennini D’Andrea Cennino in the early 15th century. Using the pad printing method should result in thin layers of varnish being applied, but there is no shrinkage from solvent evaporation and each varnish layer can be very strongly coloured. After some practice you will find it very easy to produce a miraculously uniform coating with this method. Using pad does not! exclude the use of brushes. There is no rivalry between these two tools. A clever craftsman will always use what ever combination of techniques gives the best results with the least effort.
As indication:
1 thin layer of varnish on a violin will contain approx. 3 grams of Vernice Liquida type varnish.
1 thin layer of varnish on a cello will contain approx. 13 grams of Vernice Liquida type varnish.
The following are high estimates for the total amount of Lacca Rubia pigment used on an instrument:
Violin 1 ½ grams
Cello 6 grams
- Dab the varnish onto the instrument with a stiff brush as evenly as you can.
- Next with an almost dry softer brush gently ‘’tap’’ varnish into the tightest corners of the edgework and scroll.
These areas can be difficult to reach even with your fingers (the preferred pad for most areas).
- Now gently tap your pad alternatively onto the fattest and leanest covered areas, going al over the instrument.
In this manner you can ‘’print’’ on the same spot as often as you need or like to. 2 impressions per second is
a good speed and still manageable on larger instruments. The fleshy area of the human hand palm as well as
the tips of the ring and middle finger are perfect pads and seem to have evolved especially for this purpose.
When done, it is easiest to clean the varnish off your hands with soap, alcohol, a nailbrush and some sand.
With each consecutive tapping or printing operation the varnish layer is split exactly down the middle.
Ultimately the visco-elastic properties of the varnish will force the layer to become perfectly even all over.
- Do not add any solvent once you have started varnishing !
Variation in viscosity will cause variation in tack (stickyness) this in turn will result in uneven layer thickness.
- Vernice Liquida thinned down with fast solvents can be brushed on initially and tapped to perfection after
the solvent has evaporated. With a slower solvent (e.g. petroleum) tapping can be done at any stage.
- Be careful not to apply the varnish too thickly !
If a layer is applied too thick “orange peel” effect and ultimately running of the varnish may be the result.
High temperatures during drying may then cause the varnish to run.
To avoid this, start of with too little varnish. You can always add more during the process.
You can also pre dry varnish in the shade or grind in transparent filler materials to avoid temperature induced
running. If the varnish stands up in little droplets or the wet surface is very slippery, there is too much varnish.
This can be removed with some cloth, or by tapping the excess onto a still unvarnished part of the instrument.
- Stiffer brushes (e.g. bristle glue brushes) work better for the initial application of the varnish.
Brushes used for tapping the varnish into tight spots can be softer and springier e.g. ox hair or long bristle.
- A paint roller can be used for larger instruments. In principle this tool functions like a pad.
It was already advised in the 15th century to use a sponge rolled under the handpalm as alternative to a pad. | 
