Dewaxed vs. Waxy Shellac: When It Matters
Wax-in (waxy) shellac is shellac as it comes: the resin with the few percent of natural wax the lac insect built into it. Dewaxed shellac is the same resin with that wax removed. The wax matters in one situation: under an oil-based polyurethane or a waterborne finish, where it can get in the way of the next coat bonding, dewaxed is the standard choice. Everywhere else, including French polish, as a finish on its own, under lacquer, under an oil varnish, under wax, or under more shellac, the classic wax-in flake is exactly the right material, and has been for two hundred years.
Neither one is a lesser product. The question is only what goes on top.
What the wax is
Lac resin comes off the tree with a small amount of natural wax in it, a few percent by weight. Wax-in flake and button lac keep it. In the jar, a wax-in mix has a faint haze from the wax; that haze is normal, and it does not show in the dried film. Dewaxed flake has the wax filtered out at the refinery and dissolves water-clear. “Dewaxed” began as an industrial grade in the 1930s; the furniture trade finished with wax-in shellac for the century and a half before that, and much of it still does.
Choosing by what goes on top
| Situation | Dewaxed | Wax-in |
|---|---|---|
| Under oil-based polyurethane | The standard choice | Not the choice here; the wax can reduce the bond |
| Under a waterborne finish | The standard choice | Not the choice here, for the same reason |
| Under lacquer | Works | Works |
| Under oil varnish | Works | Works |
| Shellac as the finish (brushed, padded, French polish) | Works | The classic material for it |
| Under paste wax | Works | Works |
| Under more shellac | Works | Works |
| Sealing knots and sap before paint | Works | Works |
Where “always use dewaxed” came from
The advice is everywhere, and it started from something true and narrow: polyurethane makers in the 1970s printed “do not apply over shellac” on the can, finishing authors in the 1990s narrowed that to “dewaxed is fine under poly,” and a dewaxed sealer was sold on exactly that point. Over the years the narrow case hardened into a general rule. The narrow case is still right: under oil poly or waterborne, use dewaxed. The general rule isn't. If the shellac is the finish, or anything other than those two goes over it, wax-in is as good as it ever was. Read more in our post on the history - The Wax Was Never the Problem
Grades and color
Wax and color are separate choices. Our dewaxed grades run from Platina and Super Blonde at the pale end through Blonde and Amber to Garnet. Our wax-in flakes are Lemon #1, the classic warm orange-amber, and Black. Button lac (Kusmi, Hemanta, Aruna, Jethwa) is wax-in by nature. Pick the wax status by what goes on top, then pick the color for the wood; Which Shellac Color Should I Use? walks through it.
How to decide
- Name the top coat. Oil-based polyurethane or a waterborne finish: dewaxed for the shellac layer.
- Anything else on top, or nothing: either works. For French polish and traditional finishing, the classic choice is wax-in.
- Choose the color for the wood.
- Mix to a cut and label the jar with grade, cut, alcohol, and date. See How to Mix Shellac Flakes.
Two things to know about dewaxed
- Blocking in warm weather. Dewaxed flake can soften and fuse into a block in summer or in transit. This is a property of dewaxed shellac from any refinery, not a defect; the block dissolves exactly the same. See How to Store Shellac Flakes.
- In solution, wax-in tends to keep a little longer than dewaxed, anecdotally. Both are tested the same way, with a drop on glass. See How Long Does Mixed Shellac Last?
FAQ
Is wax-in shellac a lesser product?
No. It is shellac in its classic form, and the right material whenever the shellac is the finish or anything but oil poly or waterborne goes over it. The koa bowl in our photographs was finished in button lac, wax and all.
Does wax-in shellac look cloudy?
The jar can have a faint haze. The finish does not. Two centuries of French-polished furniture were done with wax-in shellac and button lac.
Can I use dewaxed shellac on its own?
Yes. It works as a sealer or as the finish, and it is the choice when you want the palest possible film (Platina).
Does the wax change the cut or the mixing?
No. Same ratio, same method.
Can I use wax-in shellac under lacquer?
Yes. Lacquer and oil varnish go over wax-in shellac without trouble. The two cases for dewaxed are oil-based polyurethane and waterborne finishes.
I'm French polishing. Which one?
Either works; the classic choice is wax-in, flake or button. About Button Shellac covers the buttons.
All the guides are collected at Shellac Guides. Flakes by grade: dewaxed, wax-in, and button lac.