Vegetable-tanned leather strap flesh side up, half fuzzy and half slicked smooth, with a glass slicker and bone folder.
| |

Slicking the Flesh Side Smooth

ByPeter Joeseph 'Briefcase Maker' Kalafatis

The back of the hide is half the piece. Treat it that way.

The flesh side of vegetable-tanned leather is the underside, the face that sat against the animal, and left alone it stays fuzzy, catches lint, and sheds little threads into a pocket or onto a sleeve. Slicking is the work of wetting those loose fibers and rubbing them flat with something hard and smooth until the back goes dense and quiet. It is close kin to burnishing an edge, done over a much wider area, with a lighter hand.

Video: Pasting Down The Inside Pelt Part of Natural Tanned Leather, from Marcellino NY Briefcase Maker on YouTube.

People ask the same handful of questions about it, and the answers live mostly in the forums, where working makers have been comparing gums and glass for years. Here are six of those questions, answered from those makers and from my own pages where my own practice is on the record.

What does slicking the flesh side actually do?

It lays the fibers down so they stop catching.

A hand slicking the damp flesh side of vegetable-tanned leather with a glass slicker in one direction.

On a leatherworker.net thread about treating the flesh side inside bags, the member Billsotx says the word is slicking, not burnishing, and puts the purpose in one line: to “mat all those little fibers down so they are less apt to catch.” The thread’s starter, Skald, names the cost of leaving it raw. Dirt sticks to it, and fibers can be pulled out as loose flesh thread.

That’s the practical case. There’s a second one, and it’s about how a thing feels in the hand.

On The Art of Hand Stitching I wrote that a hand stitch has to look clean on both sides, because a stitch may look good outside while hidden layers hold the problems. The flesh side is the same argument for a whole panel. An unlined strap, a card slot, the inside of a flap: the back is the part a hand touches every single day, and fuzz there tells the owner something about the maker before they ever look at the front.

Not every piece needs it. A back that gets glued to a lining never sees daylight, and one later question deals with that.

What do you rub into it?

Water, gum, soap or a sealer, and the forums argue about all four.

The list is short, and each item has its defenders.

  • Gum tragacanth. On the bags thread, RicsLeather recommends a light coat followed by a bone creaser, repeated across the back. On a thread about slicking the flesh side of belts, Dan Hammons rubs gum trag in with a deer antler while it dries, leaving the back smooth without fibers showing. Fiebing’s gum tragacanth page writes its directions for edges, but the steps travel well: a small amount, spread evenly, rubbed with moderate pressure until smooth, repeated, then left to dry completely.
  • Tokonole. Weaver’s Tokonole page sells it as a water-based alternative to gum tragacanth and notes that finishes or pigments go on top of it. The page talks about edges. Flesh-side use comes from the makers: on a thread about slicking down the flesh side, SUP dilutes it and works small sections so little gets absorbed.
  • Saddle soap. Scary Leatherworks, on the bags thread, uses saddle soap, canvas and elbow grease, and notes it darkens the leather slightly. On the slicking-down thread, JDFred uses water with glycerin saddle soap.
  • A sealer. Several members reach for Tan-Kote. TwinOaks says it smells like gum tragacanth.

I’d start with plain water and a slicker on a scrap, before buying anything. If water alone lays the back down, the gum is a cost with no job.

What do you rub it with?

Anything hard, smooth and wide enough to cover ground.

Macro of leather flesh side fibers, raw and fuzzy on one side and slicked flat on the other.

This is where the forums get inventive. On the slicking-down thread, DieselTech uses “a heavy thick drinking glass,” and SUP uses a glass slicker or a glass coaster. On a thread about a veg-tan flesh side plagued with fuzz, Sam I Am rubs with beveled glass, DarkGoku uses a grass burnisher, and KingsCountyLeather suggests a bone folder or beveled plate glass. Randy Cornelius, on a thread about gum tragacanth on the flesh side, rubs with canvas or denim. Dan Hammons uses the antler.

Glass is the common thread for the wide areas. It’s flat, it’s slick, and it doesn’t care how much gum you put under it. A bone folder fits into the corner where a panel meets a fold.

One homemade tool deserves a mention. On the belts thread, CitizenKate built a slicker by wrapping veg-tan around a piece of half-inch fiberboard and cementing it down. The method in that post is to spray a topcoat on the flesh side, slick it while it’s still wet using the edge of that slicker, let it dry, and go again once or twice. Leather rubbing leather. There’s something right about a tool made from the scraps of the job it does, like a rag cut from a worn-out shop apron.

Wood works too, but wood drinks. A slicker that has soaked up gum for years is a fine tool for an edge and a slow one for a whole strap back. Pick the tool by the size of the job, the way you’d pick a trowel for a patch and a float for a slab.

How do you actually do it?

Damp, one direction, light pressure, and let it dry before you judge it.

Put the methods from those threads side by side and they agree more than they argue.

Deal with the worst fuzz first. On the fuzz thread, DarkGoku sands with 220 grit, working one direction. TwinOaks, on the bags thread, shaves stringy flesh sides with a sharp razor, the way you’d shave wool felt. Bikermutt07 says splitting off as much of the loose flesh as possible helps, and KingsCountyLeather found it helped only a little. KingsCountyLeather also suspects that bad fuzz comes from the hide itself, not the finish.

Then wet it. Sam I Am wets the flesh side, rubs it in one direction with the glass, and lets it dry fully. DarkGoku wets it and works it down with the burnisher, same direction. On the slicking-down thread, SUP gives the most useful stroke advice: long strokes in one direction toward the edges, and the technique “does not require much pressure.”

If the grain side has been tooled or stamped, protect it. Littlef lays a soft cloth under the work and keeps the stamped side dry. DieselTech’s version is shorter: don’t get too crazy when slicking.

Then the finish, if you want one. Billsotx goes over the dried, slicked back with paraffin. DarkGoku puts the Tan-Kote on last so it doesn’t block the sealer on the grain side.

Will it crack, or stop the glue from holding?

Thick gum cracks. Slicked leather is the wrong surface for glue.

Open unlined vegetable-tanned leather case with a slicked smooth interior, beside a roll of suede lining.

Gum trag has a weakness on a surface that bends. On the bags thread, moeg says it slicks well but can crack when the leather flexes. On the flesh-side gum thread, RobDude30 says his gum trag back didn’t hold up well and had the look of cracking, and suspects he laid it on too thick. Randy Cornelius dislikes gum trag because it gets where you don’t want it.

That points to two rules. Thin coats. And a strap or a flap that bends every day wants the softest treatment that still lays the fibers down, which may be soap and canvas instead of gum.

Glue is the other trap. On a thread about flesh-side fuzz and glue, Tiara notes that roughing smooth leather before gluing is often recommended, and Cyberthrasher says the fuzz itself acts as a roughing up that gives the glue something to grab. No one in these threads tested glue on a slicked back. The sensible move is plain enough without the test: keep gum and slicking off any surface that’s going to take contact cement.

Why not just line it?

Here is where I argue against the whole post.

A lot of good makers skip slicking entirely. On the belts thread, steveb lines all his belts, usually with pig, and says his earlier unlined ones never had the same feel: “lining is the way to go.” Pea-aire glues a wider belly piece behind the blank and trims it after, and says the burnished edge hides the glue seam. On the bags thread, RicsLeather suggests a pigskin or other light lining leather, and Billsotx points out that you can order flesh-side-treated leather, sold as mossback or gummed, and save the work.

So the honest answer to the question is that lining often beats slicking. It covers the fuzz completely. It never cracks. It stiffens the piece, which is often what a strap wants anyway.

I still lean the other way on a thick case. On my Leather Choices page I wrote that Hermann Oak bridle is already thick, and that with a suede lining it gets even thicker, so I usually recommend keeping the natural lining. Unlined thick veg-tan ages like harness leather, and a lining hides that back from ever aging at all.

Lining isn’t free either. Lined cases get stitched edges to hold the lining; unlined ones don’t need it. I weigh calf suede, which is more luxurious but needs care around liquid and ink, against a bridle lining, which is a little more durable and wipes clean. Every one of those choices adds leather, glue, time and a seam.

So I make the case for the bare back, and then I admit the lining crowd has the better argument for anything thin, soft, or flexed all day. A slicked flesh side is the right answer for a thick piece that’s meant to show what it is on both faces. On a belt, the man with the pigskin probably wins.

Fiebing’s Gum Tragacanth, 4 oz: A 4 oz bottle of gum tragacanth, a burnishing aid for leather edges. See it on Amazon (affiliate link).

CBHGFEA Glass Slicker for Burnishing with Walnut Handle: A glass slicker with a walnut handle for burnishing leather. See it on Amazon (affiliate link).

DEEDYGO Genuine Bone Folder: A genuine bone folder for creasing and burnishing. See it on Amazon (affiliate link).

Wet Dry Sandpaper Assortment, 45 Pieces: A 45-piece wet and dry sandpaper assortment that starts at 400 grit. See it on Amazon (affiliate link).

Barge All Purpose Cement, Quart: A quart of solvent-based contact cement. See it on Amazon (affiliate link).

As an Amazon Associate I earn from qualifying purchases. A commission may be earned if you buy through this link, at no extra cost to you.

Sources

You Might Also Like

Similar Posts

Leave a Reply