I’ve recently been using my green stropping compound quite a bit before using my edge bevelers, and I wanted to learn more about the different kinds of strop compounds out there. Let’s take a closer look at what leather strop compounds are and what they have to offer.
Leather strop compounds come in four colors mainly: black, white, red, and green. They all vary in grit, and the most common compounds are the green compound and white jeweler’s rouge, both of which cost between $8-10 for a bar that will last a very long time.
With all the different kinds of leather compounds out there (including polishing pastes!), it’s helpful to know what we’re getting into when we start working strop compounds into our regular rotation. Let’s look at which strop compounds will be most helpful to you in maintaining and polishing your tools.
History of Leather Strop Compounds
Though it is unlikely the first leather strop and strop compound ever made, a 1794 ad by George Packwood in the London Times tells us that back in 1794, he was advertising his razor strop and strop paste in the London Times. If you’re curious for what George Packwood looks like, here is a 1796 engraving of him by A. Walkinshaw, held at the British Museum.
Since then, leather strop compounds have grown in number, and this trend is not likely to stop given the increase in attention paid to keeping knives (especially chef’s knives) sharp. (People taking up pandemic hobbies likely contributed to this!)
For leatherworkers, strop compounds are critical to have around the workbench in order to keep our knives, edge bevelers, and skivers sharp. Stropping is slightly different from sharpening, as this study by John D. Verhoeven at Iowa State University on experiments in knife sharpening demonstrates.
Types of Leather Strop Compounds
The next most common strop compound is probably the green strop compound, which is often applied to leather strops and is made of aluminum oxide and chromium oxide. This is useful for sharpening up tools before using them.
There are a few different kinds of leather strop compounds. For starters, there are the different colors of “crayon” compounds – these seem to be the most common option when one is looking for leather strop compounds. There’s the common jeweler’s rouge, which usually comes in a reddish brown color; usually, it’s used to achieve a polish more so than honing or sharpening the tool.
The next most common strop compound is probably the green strop compound, which is often applied to leather strops and is made of aluminum oxide and chromium oxide. This is useful for sharpening up tools just before using them. The other two most common colors are black and white. The black compound will take off the most material from the edge of the your tool, so it’s preferable to apply it before sharpening a tool that’s a bit more dull.
The white compound is very fine, so it won’t have much effect on tools that are in need of a bit more sharpening. However, it will be effective for reaching a mirror finish on your tool after sharpening has been done. Something also worth noting is that these colors are not exactly standardized; some brands of strop compounds actually have the white compound as the coarsest, so be sure to pay attention to what reviews are saying about the particular compound you’re looking at purchasing.
There are also polishing pastes that can be used as leather strop compounds as well. Some think that these pastes get embedded in the leather strop, which allows for a surface that develops and becomes better and better at retaining the polishing compounds. Sometimes, these pastes are used by woodworkers for woodworking tools, which means that they are likely good enough for leatherworkers as well.
These will work by squeezing it out (kind of like toothpaste) onto the leather strop and then rubbing it in before stropping your tool. Whether one chooses the “crayon” compounds or the polishing pastes comes down to a matter of preference.
Below is a nice video explaining different leather strop compounds in depth:
Characteristics of Leather Strop Compounds
Leather strop compounds can feel kind of like crayons, as mentioned above. However, the finer the compound, the more chalky and smooth it may feel, since the high grit is necessary for polishing and refining tools after lower grits have been used to create the burr.
These compounds are applied in a similar way to drawing with a crayon; just rub it against the surface of the strop as if you were trying to color it in (though it may be wise to avoid completely coloring the strop with the compound, as this may diminish its effectiveness).
Leather strop compounds come in a variety of colors; assuming that the materials within the compound are the same chemicals without any added coloring, the following table can describe use cases for each color.
|Black||Remove the most material when stropping||Emery|
|White||Remove and polish metal||Aluminum oxide|
|Green||Remove and polish metal (often finer than white)||Chromium oxide|
|Red||Polish metal||Ferric oxide|
As for the leather strop compounds of the paste variety, they have been described to be kind of gritty, like certain kinds of toothpaste. Some take this to mean that more of the material is being taken off, but it does come at the cost of a subjectively less pleasurable texture. If you happen to like the grittiness, more power to you!
Helpful Items to Begin Stropping
Here is an easy-reference table with paid links to items that I trust – these are a great place to start with the various compounds.
Pros and Cons of Leather Strop Compounds
Pros of Leather Strop Compounds
- Buying leather strop compounds to strop tools with is cheaper than buying expensive tools
- Leather strop compounds are easy and quick to apply
- Wide variety of options for strop compounds to use
Cons of Leather Strop Compounds
- Using strop compounds can be tedious for people who don’t want to sharpen their tools
- Leather strop compounds will require a strop
- Can be confusing to know how which strop compound to buy
How Leather Strop Compounds are Made
Though leather strop compounds are very cost effective, it can be interesting to know how leather strop compounds are made. As mentioned earlier, the green stropping compound is made of aluminum oxide and chromium oxide. However, in order to get the “crayon,” wax is melted first and then the aluminum oxide and chromium oxide powders are added in. Then, when the mixture is runny, it can be poured into a mold of some sort. After it hardens in the molds, you just take it out and you have your leather strop compound.
This is a video by James Wright demonstrating how he makes his leather strop compound:
Cost of Leather Strop Compounds
Leather strop compound is generally very inexpensive; you can find six bars for around $16 or a large bar of Dialux for about $8. When you consider the fact that each of the six bars can last at least two or three years (and likely longer than that with a regular amount of stropping), leather strop compound is one of the most cost effective elements of leathercrafting.
Tips for Working with Leather Strop Compounds
- Apply leather strop compound to the grain side of the leather strop (though sometimes, you’ll see strops with the flesh side exposed)
- Contrary to popular marketing, covering the leather strop in stropping compound may actually reduce the effectiveness of the strop compound on sharpening your tools. Cover the leather with just enough compound to see some of the leather, but avoid covering it entirely with the compound so that it looks like you’ve colored it in.
- Charge strop compound often! Since you don’t need to absolutely coat your leather strop in compound, frequent applications of light coats of compound is the way to go when sharpening/polishing your tools. Strop before using your tools to reduce how much time you need to spend actually sharpening your tools.
Cover the leather with just enough compound to see some of the leather, but avoid covering it entirely with the compound so that it looks like you’ve colored it in.
Hearing from the Pros on Strop Compounds
I reached out to some leatherworkers for some more experienced information about strop compounds, and I actually learned quite a few things. When making a leather strop, using a strip of chromexcel or tight grained leather like latigo is preferable. If you want to make a strop yourself, make sure to glue it so the grain is facing upwards, and charge it with strop compound before stropping. The softness and springiness of the grain is what helps the edge of the tool get stropped effectively.
Having a two-sided leather strop will allow you to have two different degrees of coarseness to strop with. Coat one side with the coarser compound and the other side with the finer compound – this will allow you to move from the coarse side to the fine side and get the edge of your tool as polished as possible.
The last tip I found was that if looking at all the different kinds of compound is overwhelming, go with white jeweler’s rouge. Many leathercrafters have sworn that this is the only one they’ve ever needed for all of their stropping purposes.
Leather Strop Compound Care and Maintenance
Store your leather strop compound somewhere cool and dark, as the waxes in the crayon-style compounds may melt if exposed to higher temperatures. Beyond this, not much has to be done. It will take a long time to use up a bar of strop compound, so apply it often to your leather strop, then store it in the box it came with.
What grit is green compound?
Green compound is usually made of chromium oxide (though nothing is preventing strop compound manufacturers from adding coloring. However, it is usually 60,000 grit and it is best used for stropping your tools right before using them; it does not take much material off, so using it frequently will yield the best benefits.
Do you need stropping compound?
If you plan to have a razor sharp edge on your tools or you want to avoid sharpening your tools as often, stropping compound can certainly help with that. However, it can be enough just to have a piece of leather with tight grain to use as a strop.
Can you use polishing compound for stropping?
Polishing compound can be (and is) used for stropping – this is a common practice in woodworking. It usually comes in a tube much like toothpaste, and it often has the texture of toothpaste as well. You’ll simply apply the polishing compound to a leather strop, and strop as normal.
Strop compound is a really useful, inexpensive substance to keep on the workbench. I keep a small bar of green strop compound that I apply to a leather strop before each time I pick up a knife or edge beveler. I hope that learning about strop compounds has encouraged you to go out and buy a bar yourself – it’ll make a noticeable difference to how smoothly your leatherwork goes!