Properly Casing Leather

 From seasoned veterans to greenhorns, casing leather can be a trying task for many of us.  This is compounded with the fact that different brands and tannages of leather can react much differently to our standard casing process.  This makes it difficult sometimes to achieve the results that we want in our leather projects.

In this article I will discuss my process for casing leather and how I adapt for different thicknesses in order to get that perfect water content for carving and stamping.  I will also touch on casing leather during forming and how I case leather parts that require gluing during the forming process.

What is Casing leather?

“Casing” leather is the process of adding water to vegetable tanned leather.  This is done to soften the fibers of the leather to achieve many tasks within a leather crafting project.  These tasks can include carving with a swivel knife, stamping, forming and skiving or thinning down of leather.  Vegetable tanned leather has been tanned but is still in a bit of a raw state which allows the craftsman to introduce water easily into the fibers of the leather.  This is what is called “casing” and is an essential skill that must be learned.

Traditional Casing

As with everything in any trade industry, there is much debate on the proper way to perform any task.  But for the sake of this article, I am going to describe the “Traditional” act of casing leather as I was told and leave the debate for those masters that know more than I do on the subject.

In the traditional sense, to properly case leather you would completely submerge the piece of leather that you plan to carve, stamp or form.  This is usually done in a shop sink, bathtub or plastic bin filled with fresh clean water.  The piece of leather is allowed to stay in the water completely submerged until no more bubbles are seen coming from the leather.

At this point the water has penetrated completely throughout all the fibers of the leather and the piece is completely saturated.  The leather is then removed from the water allowing the excess water to drip off for a moment.  Next the leather is put into a plastic trash bag and the bag is tied shut with as much of the air removed as possible.

The leather is then allowed to set in the bag to sweat or “case” for a few hours or overnight.  If the leather is not needed for more than a day, then the bagged leather can be stored in the refrigerator for a week or so to prevent mold growth and maintain its case.

When the leather is ready to use, the leather piece is removed from the bag and allowed to air dry flat on a work surface.  This is where the judgment of the craftsman comes into play.  There is a point during the drying process when the leather has an optimal moisture content for carving and stamping.  Being able to recognize this window of opportunity is the tricky part sometimes.  As the leather begins to dry out it becomes lighter in color.  The perfect time to carve is somewhere near the point at which the leather is almost back to its dry color range but still wet.  Many craftsman have tricks for deciding when this time is, but the one that I was taught is what I call the thumbnail method.

When the color looks like it is getting closer to dry leather color, I will simply press the tip of my thumbnail into the grain side of the leather (in a spot I will tool over or that won’t be seen).  I am looking for two things here.  First is “how does the leather take my impression?”  I can usually tell if it feels spongy or if it has a bit of “crust” to it or temper.  This crust tells me that when I carve with my swivel knife or strike a stamp on the grain of the leather, that the integrity of the fibers will support the impression and my cuts will open up and stand firm.  This is important to insure good impressions and contours during the tooling process.

The second thing I look for is the “color of the impression.”  Here I am looking to see if the deepest part of the impression turns a darker color than the rest of the leather.  This is the “burnish” that adds to the contrast of the final tooled piece.  A good quality veg tanned leather will turn nice and dark when a stamp is driven into it.  If the thumbnail impression doesn’t turn dark then the leather is probably still too wet and the dark contrast will not show in the final piece.  There are some lower grade veg tanned leathers on the market that just don’t have a good burnishing quality about them.  Take this into consideration if you are casing these leathers.

If my thumbprint has the feel of good crust and burnishes well enough, then I am ready to begin the tooling process after the few hours of traditional casing.  Did I mention the “hours” it took to get to this point using the traditional method?

This is where I will confess that I am not a traditionalist when it comes to my casing method.  This is where I talk about the method that I use daily in my shop on all my projects and I call it a “Quick Case.”

What is the Quick Case?

The Quick Case method is what more craftsman are familiar with because of its speed and efficiency.  In a perfect world, the craftsman should be organized enough in his or her work to have parts cut and cased (traditionally) in advance ready for the project ahead.  Since I do not live nor operate in a perfect world, and I will assume that few of you do either, I have to use a casing method that allows me the flexibility to start and finish a project in the shortest amount of time possible in order to run my business efficiently.

In this method, I do not allow for the leather to saturate completely on my thinner leather pieces.  For a belt for instance with a weight of around 9/10 oz leather for the top that will be tooled, I simply use a spray bottle with clean water in it and spray the blank to get a good saturation.  On the first spray of the belt, I will really try and get a good saturation… much more wet than I want it to be to start.  This step is kind of like priming the pump so to speak.

I will then allow the blank to sit on the bench and begin its drying process.  Since I did not submerge and over saturate the leather, it will get to the perfect casing point much quicker.  Once it has reached this point, then I will begin my carving and tooling.  Throughout the tooling process I will monitor the moisture content of the leather.  As it begins to dry out, I will see how the leather is reacting to my tools and if it seems to be getting a little too dry for the tools I am using at that moment then I will spray it lightly to get it back where I need it.  The beauty of this method is that you can regulate the moisture content at different stages of the tooling for different tools you are using.

For instance, when I am carving and beveling I want the leather a little on the dry side so that my cuts and bevels are firm and crisp.  This goes for my bar grounding as well.  On the other hand when I am pear shading I want the leather to be slightly higher in moisture content so that I get a more fluid impression.  Finally when I do my final step which is relifting all my undercuts and adding in my decorative cuts, I will give it a fresh spray so that the leather is receptive of the tools a little easier for a cleaner look.

Since we all have a difference in the order of the tools we use when floral carving, the times when each of us would regulate the water content is different.  With the spray bottle you are able to adapt this to fit your tooling rhythm.

I use this method for the majority of my tooling projects and it works very well for me.  The only time that I will submerge a piece of leather is when tooling a thick piece of saddle skirting like a fender or skirt.  Even with this though I do not allow the leather to stay in the water very long at all… it’s more of a “dunk and remove” type maneuver.  Since the leather is much thicker, I want to get a lot of water into the leather fast and then maintain the moisture content with my spray bottle throughout the tooling process.

A side note for using the quick case method:  I draw my artwork on to the leather directly with an art pencil and I want the leather absolutely dry for this step.  If I was to use a traditional casing method I would have to draw my artwork and then case and wait for some time before actually carving it in and tooling.  This way, I can draw, carve and tool all in the same setting.

Also, the majority of my smaller projects are lined with a poster board stiffener to prevent stretch and to add body to the final project.  If I was to use traditional casing then the integrity of the paper would be destroyed by the water during casing.  The Quick Case method allows me to apply water in a controlled manner only to the grain side of the leather protecting the poster board.

Casing for Other Tasks

Casing leather is more than just for stamping or tooling.  This is just as important for other applications and tasks like skiving, forming, and stretching leather during projects.  Many issues during projects can be caused by improper casing of the leather.

Skiving

It is virtually impossible to make anything out of leather and not have to do some hand skiving during the process.  If you are working with mainly latigo or harness type leathers then this is probably not a big issue for you.  But if you are using veg tanned leather, then you have certainly had the situations where no matter if you are using a head knife or a safety skiver with good razor blades the leather just seems to fight you when you attempt to skive it down to a nice feather edge.

This is where a little water can go a long way to save you some time and do cleaner work.  When the leather is properly cased and wet, skiving becomes more controlled and fluid.  This is especially true if you are trying to level a large piece of leather for say a cantle back or a swell cover.

If I am thinning down the fold end of a belt or breast collar piece, I will usually use the Quick Case method for this.  This will allow me to control the amount of water that I am applying so that I can apply glue if I need to when I am done skiving.  Contact cement does not adhere to wet leather well at all so I don’t want it too wet or have to wait for it to dry out before applying glue.

When I am leveling and preparing a cantle back or swell cover I will fully submerge these pieces so that the water penetrates completely through the leather.  This will allow me to be able easily remove material in large swipes with a safety skiver and maintain an even thickness much easier than if it was dry.  This will also save the number of blades that I will have to use to accomplish this.  As this leather has been completely saturated, I will have some wait time for it to dry before applying contact cement for installation.

Forming Leather

Forming leather in different projects can sometimes be difficult and getting the case right here is very important.  For instance, when I cover a swell on a saddle the case of the leather has to be just right.

Take the swell cover we previously mentioned and skived.  This piece has had time to dry completely… usually a day… and now I am ready to install it onto the tree.  In order to do this, I need to have the swell cover cased completely so that it will easily take the shape of the front during the forming process.  I also need to glue this swell cover to the tree so that it stays where I want it for the life of the saddle.  Since wet leather does not accept contact cement well at all, I will apply two good coats of contact cement to the leather swell cover as well as the front of the tree where it will go allowing each coat to dry completely before moving forward.

Once the glue is completely dry I will submerge the leather into my sink of clean water and allow it to sit in the water for a few minutes.  The time depends on the leather’s reaction to the water… sometimes it gets soft quickly and sometimes I need it to be in there a little longer to completely soften.

The neat thing about this is that the glue we applied and allowed to dry will stay stuck to the leather.  This gives us a good glued surface on the wet leather that will stick well to our glued front on the tree.  I remove the leather from the water and use paper towels to dry off the glue side of the swell cover.

At this point I will apply a quick thin coat of glue to the swell cover just to freshen up the contact cement that we already applied.  This method works anytime you need to form wet leather and want to be able to glue it at the same time.  There are applications where you would prefer to form the wet leather and then remove it from the object and allow to dry before gluing.

Stretching leather

There are situations when you want to take the stretch out of the leather for a project or maybe you need to stretch a belt that was too small (hopefully you have read my article “How to measure belt size“).  I have heard of a few saddle makers that stretch their stirrup leathers on saddles they make.  They may cut the black 4″ wide and case the leather really well and stretch the leather greatly and after they are dry they will cut them down to the standard 3” width.  This is to insure the leathers will not stretch during the life of the saddle.

Stretching is pretty straight forward as far as casing.  You want to have it cased to the point that the fibers of the leather will accept the pressure from the stretching process and allow them to be stretched to their maximum capacity.  This is very important in the bootmaking process when stretching vamps.  This helps to form and shape the boot vamps around the last for the customer.

Conclusion

Casing leather takes a bit of trial and error to get the hang of and is somewhat of a personal preference.  But whatever process you prefer to use I am sure that with time and practice you will begin to learn the ins and outs of casing that works best for your program. The best way to learn your casing preference is to submerge or spray some leather and get after it.  The worst thing that can happen is you have to throw it out.  Remember, it’s only leather and there’s more where that came from!

I hope you found this article useful and shoot me an email with any questions or let me know what your process is for getting just the right water content into your leather.  Thanks so much!