Introduction
French polishing is a highly specific finishing technique applied to fine wooden surfaces — furniture, and above all musical instruments. The varnish is prepared by dissolving shellac in 95% alcohol, then applied with a pad (called a rubber) made of wool wrapped in soft cotton cloth.
Charged with shellac and alcohol, the rubber moves in continuous circular or figure-eight motions across the surface of the instrument until it becomes nearly dry. Each session is followed by a resting period, and the process is repeated multiple times to gradually build the finish. The experience, sensitivity, and control of the luthier are essential throughout. Additional resins — benzoin, sandarac, rosin — may be added to modify the working properties or tonal character of the finish.
Wet pad
Apply with very light pressure. Excess alcohol dissolves already-applied layers — known as "burning" the finish. If material needs to be removed, squeeze the pad in a cloth.
As it dries
Increase pressure gradually as the pad becomes drier during the session. Follow the wood — the rubber does the work.
Nearly dry
Use a near-dry pad for delicate or hard-to-reach areas. A near-dry pad is the most controlled tool in the process.
I
Session organisation
Order
Each session follows the same sequence, repeated until sufficient film thickness is built up. After five to seven sessions, the base layer is complete and levelling can begin.
Back of the instrument, then back of the headstock once the pad is nearly dry.
One side (rib), then the side of the headstock and heel.
The opposite side, following the same procedure.
The soundboard, finishing with the headstock face and bridge.
The back of the neck.
II
Materials & preparation
Several types of shellac
Dewaxed blond shellac (in two shades) is used for the ground coats. Arathoune is applied later to give the instrument its warm honey tone. Shellac flakes take several days to dissolve in 95% alcohol — preparation must be anticipated. The solution must then settle so that wax sinks to the bottom; the clear dewaxed varnish is drawn off with a syringe and filtered through a coffee filter.
III
Application & technique
First coats without oil
A cloth lightly soaked in shellac is first passed over all the purflings to "fix" the colours. The initial coats are applied without oil, helping to fill the microscopic pores of the spruce. The motion is circular or figure-eight shaped — and it must never stop. The hand begins positioned like an airplane coming in for landing and finishes in the reverse position, ensuring fluidity and even coverage.
Edges & difficult areas
Edges and corners — particularly around the purflings — are more exposed to wear and must receive adequate build. To reach tight corners, a small fold of cloth is shaped with the fingertip and lightly charged with varnish. Careful dosing is essential here.
Storing the pads
Between sessions, polishing pads are stored in airtight jars to prevent them from drying out. The rubber is a living tool — its condition directly affects the quality of every session.
IV
Levelling & sanding
After five to seven sessions, the base layer has reached sufficient thickness. Levelling can begin.
Sanding to a uniform matte
Sanding is always carried out in the direction of the wood grain. Pressure must remain very light — the sandpaper does the work. Shiny spots indicate areas that have not yet been levelled. Sanding continues until the entire surface is uniformly matte.
Levelling sequence
The final levelling stage uses 600-grit paper, followed by 800-grit to remove any remaining scratches before colour coats begin.
V
Colour coats & completion
The darker shellac & the comet tail
At this stage the darker shellac (arathoune) is applied using a slightly drier pad with a small addition of oil. The visible "comet tail" following the pad's movement is the alcohol evaporating — a sign that the varnish is flowing and setting correctly.
The movement must never stop — the hand begins like an airplane coming in for landing, and finishes in the reverse position.
Neck, corners & headstock
The neck is polished following the same principles as the body. Certain areas — the sides of the bridge or fingerboard — are difficult to reach; a softer section of cloth may be used, with varnish applied locally with the finger just before application. At the end of each session, the headstock surface is revisited with an almost dry pad.
Final polishing
To achieve a uniform colour, the pad's path must remain consistent across the entire surface. Lingering too long in one area creates darker patches. As the instrument nears completion, a nearly dry pad charged with pure alcohol and a single drop of shellac removes residual oil and enhances clarity and gloss. A traditional polishing compound ("popote") may also be used.