Shellac for Musical Instrument Finishing — Button Lac & Pale Grades for Luthiers

Why luthiers use shellac

A shellac finish is built from many very thin coats, usually by French polishing with a pad. It gives a thin, hard, glossy film, and because fresh shellac re-dissolves the coat beneath it, scratches and worn patches can be repaired and blended in without stripping the instrument. It also works as a sealer under other finishes. We make no claims about sound: finish choice and film thickness are decisions for the luthier.

French polish on classical guitars and early instruments	Button lac for a deep amber tone, or Lemon and Blonde dewaxed grades
Pale finishes on spruce and maple	Platina or Super Blonde dewaxed shellac to keep the wood light
Sealer under oil or spirit varnish	Dewaxed shellac, so the topcoat bonds
Repair and touch-up	A grade matched to the original colour; shellac blends into an existing shellac finish

Waxed or dewaxed

Waxed shellac — button lac and standard shellac flakes — is fine when shellac is the whole finish, and many finishers like its warmth. If any other finish goes over the shellac, use a dewaxed grade, because natural wax can stop the topcoat bonding. Dewaxed vs waxed shellac covers this in detail, and button lac vs shellac flakes compares the two forms for French polish.

Working notes

• Mix only what you will use: dissolved shellac has a short working life. A 2 lb cut is about 240 g of flakes per litre of alcohol; French polishers often work thinner.
• Store dry flakes and buttons cool and sealed, and use stock in date order — warm storage reduces solubility.
• Alcohol is flammable: work with good ventilation and away from open flames, and dispose of polishing rags safely.

What to put on the specification

State the colour grade, waxed or dewaxed, and form (flakes or buttons), and ask for a fresh lot with wax content and insolubles measured on the batch COA. For colour matching, order samples of two neighbouring grades and compare them on your own wood.

How we supply luthiers and suppliers

We supply button lac, shellac flakes and dewaxed grades from Platina to Garnet to luthier-supply distributors and workshops — button lac and flakes from 100 kg, dewaxed grades from 25 kg — with a batch COA. Samples of 100–500 g are available for colour matching. Italian buyers can also read our Italy guide, which covers lutherie.

Quick answers

Which shellac is used for French polishing a classical guitar? Button lac and pale dewaxed grades such as Lemon, Blonde or Super Blonde are the usual choices. Pick by the colour you want on the wood, and test on an offcut first.

Can a shellac finish on an instrument be repaired? Yes. Fresh shellac re-dissolves the coat beneath it, so worn areas and scratches can be built up and blended in without stripping the whole finish.

Waxed or dewaxed shellac for instruments? Either works when shellac is the complete finish. Use dewaxed shellac as a sealer under oil, spirit varnish or any other topcoat, because natural wax can weaken adhesion.

This guide summarises publicly available information and industry practice as of October 2026. Run your own trials and check the rules for your market before ordering. It is not legal advice.