Leather is expensive—you want to get the cut right the first time, every time. While it may seem like a trivial topic for a post, the ways to cut leather are not necessarily immediately obvious to beginners to the craft.
First and foremost, it is highly advisable to create your designs using vector-based design software such as Adobe Illustrator. This software lets you input precise measurements in millimeters for printing on a 1:1 scale. It also lets you put together your design piece by piece so you can have a sense of whether the design is going to work from a sizing perspective (e.g. Are the card slots wide enough? Is the item big enough to comfortable hold a passport?) before you’ve made a cut into any leather.
Paper template and masking tape. Sticking down the printed paper template with masking tape around the edges of the leather and then following the lines with a utility or leather craft knife is a simple but accurate way to cut shapes. This is especially true if you want to pre-punch stitching holes in the pattern so once cut it is ready to be assembled.
For cutting thin leather (1mm or less) in a straight line some prefer a rotary blade over a craft knife or Japanese skiving knife. This is because a knife “pulls” the leather as it cuts and can sometimes stretch it at the corners when the leather is thin. A rotary blade, on the other hand, pushes down through the leather and against the cutting mat so you don’t have this problem.
Card templates. A method favoured by many. Paper templates are glued to a strong piece of card and then cut out. These templates are then marked out on the leather itself using either a scratch awl or leather pen (pens with gold or silver ink which can be wiped clean from the surface afterwards), or simply cut around directly using a sharp knife. Ideally, you will need a heavy weight to hold down the card to prevent it from slipping.
Do not try to cut out rounded corners directly with a knife. Cut the corner at a right-angle and then later cut the corner out by bring down the blade of a Japanese skiving knife and cutting incremental slices of the leather (at a tangent to the corner line) so that eventually you end up with a rounded corner (you can sand it down later to get it perfect).
Acrylic templates. Hard acrylic templates are the best way to go. Unlike cardboard, the leather knife cannot accidentally cut through the plastic giving you more accurate results. Acrylic templates can be custom ordered online.
For templates a good tip is to use double-sided sticky tape along the template edges to hold it in place. This is a much more secure method than using a weight to hold the template down—especially when working with leathers with a much more “slippery” surface, e.g. goat skin.
Laser cutters. In recent years laser cutters have come down to a price point within the reach of some leather crafters and companies like Glowforge are targeting consumers with their offerings. Fast, accurate, with the ability to alter designs on the computer and have them cut out perfectly in a matter of minutes, the advantages are obvious. However, laser printers are not without their drawbacks. Even consumer laser cutters retail for $3,000 upwards and require filtration systems to safely remove the smoke created from the cutting process. Moreover, the cutting process itself burns through the leather meaning that it needs to be cleaned up (edges sanded) afterwards.
Die cutters. Luxury brands use pre-made die cutters which are then pushed down onto the leather by a hydraulic machine (like a cookie cutter into dough). This gives a perfect cut every time without the burn marks of a laser printer, and is the best option for punching out many identical patterns for commercial use. Unfortunately, this is an expensive and impractical option for the hobbyist looking to play around with different designs.