Bleeding Sharpies & Shellac

I’m interrupting the garden gate series to delve into a matter that arose in the comments on a previous post, where I mentioned that I sometimes use a black Sharpie felt-tip pen to make the stripes on inlaid bees. A couple of readers responded that applying shellac on top of the marker would dissolve the ink, leading to smudges.

Having used this technique many times over the years without producing smudges, I was stumped. After reading the comments, I went to the shop and made a couple of marks on a piece of red oak scrap. (Typically I’m using white oak for the inlaid bees, but not always.) I let one dry for an hour before applying a film of Zinsser Bull’s Eye amber shellac with a foam brush (because I didn’t want to get out the shellac brush for an experiment). There was no smudge. With the other mark, I applied the shellac over the marker right away instead of giving it an hour. Still no smudge. In case the smudging was dependent on multiple brush strokes, I worked over the area a few times with the wet foam brush. Still no joy in the smudge-production department (which translates to joy for me in terms of my everyday work).

The top mark dried for about an hour before I applied amber shellac. I coated the lower mark immediately after making it, brushing the shellac back and forth.

I know from experience with a variety of materials and techniques that results depend on variables, among them wood species, drying time, the proportion of solvent to solids in the finish, etc. So I pulled out a few scraps of different species — hard maple, mahogany, and pine — and repeated the experiment. This time I used Zinsser blond shellac, because it seems to have a higher solvent content. Here are photos of the results.

Hard maple with blond (top) and amber (bottom). Definitely smudged.

Mahogany with amber shellac: the ink bled into the pores as I wrote the letter with the marker. When I applied shellac, it smudged slightly.

The original red oak sample, this time with blond shellac

I contacted the technical department at Zinsser (the brand is now owned by Rustoleum), hoping to get some informed insight into these results, but the very helpful staff person who took my call has, as of publication time, still not been able to get a response from the individual qualified to comment substantively. If I hear back, I will add the information to this post.

Bottom line: Always perform a test before applying any finish to a workpiece. And if you want to sign your work in black Sharpie, do so after applying a shellac finish.

Thanks to the readers who commented on my earlier post for providing me an opportunity to do this experiment.

Update

On applying Sharpie over shellac: I did a test last weekend and found that there was no smudging or apparent bleed-through. With any technique, always do a test that goes completely through every stage of finishing.

Sharpie on top of amber shellac

– Nancy Hiller

English Arts & Crafts Furniture
Projects & Techniques for the Modern Maker

By Nancy Hiller

English Arts & Crafts Furniture explores the Arts & Crafts movement with a unique focus on English designers. Through examination of details, techniques, and historical context, as well as projects, you’ll discover what sets these designers and their work apart from those that came before and after, as well as gain a deeper understanding of the Arts & Crafts movement and its influence.