All Wakker concertinas are French polished.  French polishing is a wood finishing technique, not a material.  It is a method of applying many (50 to 100) very thin coats of shellac dissolved in alcohol.  Unlike other finishes, each newly applied thin coat of shellac will be absorbed by the previous layers, resulting in one smooth layer of shellac, instead of many individual layers.

The word 'polishing' refers to the repetitive motion necessary to apply the shellac.  In the 19th and early 20th century French polishing was used on high end musical instruments because of its superior gloss and deep color. 

With the introduction of the much cheaper an faster spray finishes during the early 20th century,  French polishing was reserved only for the most exclusive instruments. The only draw back of the traditional French polishing technique is that it is very time consuming; French polishing a concertina takes up to 9 hours. On the other hand, the finish of a French polished instrument can be perfectly repaired.

We still follow the traditional 19th century method of French polishing, but use modern shellac recipes, which we make in our own studio.  The result is a tough 'invisible' finish that protects and allows the wood to breath at the same time.