Written by Nicole Alvarado, Third Year Library and Archives Graduate Fellow

Figure 1. English paring knife (drawing from Bookbinding, It’s Background and Technique by Edith Diehl)

It is essential to have a sharp knife for paring leather, but most knives, aside from the readymade knives from Jeff Peachey tools, come with their factory grind. This often means that the bevel side of the knife is often coarsely ground to the general shape required for cutting, and the flat side is not necessarily as flat as it may seem. If you have the time and the patience to sharpen your own knife, it is a great skill to have. Not only will your knife be ready for use, but you will also have a better feel for how your knife cuts, when the blade is cutting optimally, and when it is time to strop or re-sharpen your knife. Here are some tips for getting your paring knife to its optimal functionality from the comfort of your own home.

If you need to grind your knife, but don’t have a belt sander or a grinding wheel, a coarse grinding stone will do the trick. Diamond stones are relatively inexpensive and are a compact alternative to purchasing heavy equipment for grinding. Diamond stones also don’t have to be flattened before use unlike oil or water stones.

For sharpening stones, I use Jeff Peachey’s M3 PSA polishing film, though I have used water stones and oil stones and all work well, though require varying maintenance. The polishing film does not require flattening, though regular replacement of the films is needed especially for the coarser grits, which get dull relatively quickly particularly when first learning when to change grits. Water and oil stones will need to be flattened in between uses to prevent dishing. 

Figure 2. Jeff Peachey sharpening system

Only the blade edge needs to be flat. While a nice polish across the entire back of your paring knife looks nice, only about 2 or 3mm from the edge of the blade needs to be flat for a functioning paring knife. 

Start with the bottom. In most cases, you will want to start sharpening on the flat side of your knife to create a burr.

Figure 3. Sharpening the flat side of an English paring knife (drawing from Bookbinding, It’s Background and Technique by Edith Diehl)

Sharpening your own blade will help you become better and paring leather. Knife sharpening requires a lot of time spent holding and shaping your paring knife. No one will know your knife as well as you will after learning to sharpen your knife yourself. 

Figure 4. Using a French paring knife (drawing from Bookbinding, It’s Background and Technique by Edith Diehl)

Prevent injury by using safe practices in testing sharpness and handling techniques. I recommend reviewing Jeff Peachey’s Twelve Ways of Testing Knife Sharpness. Test for a burr ACROSS the blade, bot along the blade. Be sure to wear close toed shoes while knife sharpening, and NEVER try to catch your blade if you lose your grip. 

Maintain about a 13 degree angle on the bevel side of your knife. This is the optimal angle for paring leather and the closer to this angle, the better your knife will cut. Having said this, it is equally important to make sure that you are not curving your bevel as you sharpen your knife. This will drastically reduce the effectiveness of your blade. 

Figure 5. Sharpening bevel side of English paring knife (drawing from Bookbinding, It’s Background and Technique by Edith Diehl)

Make sure your sharpening surface is well lubricated. You’ll likely need to use more water (or oil if you’re using an oil stone) than you think you will. You want your knife to glide along your surface while still feeling the grit etching the surface. If your knife catches or is hard to move, then your sharpening surface is too dry. 

You will need to use some pressure. When you first start sharpening on a grit, you will need to use some pressure to effectively sharpen your knife. As you prepare to change grits, back of the amount of pressure you are using for a better transition between grits. Each grit scratches into your blade leaving scratch marks that the next grit needs to get rid of. This will be easier to accomplish if you gradually reduce the pressure you use while sharpening.  

Once you feel a burr on your blade, it’s time to switch either to the other side of your knife, or to the next finest grit. Once you get past 1200 grit or 15 micron (these aren’t necessarily equal measurements) the burr should be minimal if not undetectable. Past this point, you will have to look at your blade to determine when it is time to change grits. 

Strop frequently. Start on the bevel side when stropping so that the burr is ends up on the bevel side once finished. Once your knife is sharp, and you’ve gone through all of the sharpening grits that you desired, be sure to strop your knife. Stropping regularly as you pare leather will reduce the frequency in which you will have to sharpen your knife. It may take some time to get a feel for when your knife starts to dull and it is time to strop, but if you regularly strop after every few cuts, then your knife will remain sharp for longer. 

Figure 6. Jeff Peachey style strop

Rounding of your bevel is inevitable. At some point either from stropping or from sharpening your blade, you will end up with a rounded bevel. This is why it is so important to maintain the included angle while sharpening and stropping to reduce the quickness in which this occurs. When your bevel curves, you will have to go back to your grinding stone to re-flatten your bevel. 

At the end of the day, there is no one way to sharpen knives. These are just some suggestions that I found useful while sharpening my own knives. Thanks for reading!

For more tips and tricks to getting the most out of your paring knife check out these resources.
https://jeffpeachey.com/2011/10/18/peacheys-ten-commandments-of-sharpening/

Testing Knife Sharpness
https://jeffpeachey.com/?s=12+ways+to+test+knife+sharpness

Stropping
https://jeffpeachey.com/2012/09/18/how-to-strop-a-knife/

Bookbinding, It’s Background and Technique by Edith Diehl (drawings from here)
https://catalog.hathitrust.org/Record/001161392