Leather Bag Patterns – Now that you’ve seen how to use a pattern to create a wallet, I’m going to show you the basics of making your own patterns for simple leather designs. Patternmaking can get very technical when you’re making patterns for complex shapes, but it can also be very simple, and knowing a little about it will really help your creative process. Also, once you have a pattern for design, it makes it that much easier to re-create that project or make another version!
I use a combination of techniques to create patterns depending on the design. Sometimes I play around with cutting and folding paper first to create a general shape, sometimes I go straight to drawing a flat pattern either with pencil and paper or with a vector design program. Most often I use some combination of these techniques.
Step 1: Anatomy of a Pattern
A pattern is a two-dimensional template that has all the information you need to cut specific shapes out of a flat material that can be assembled to form a design. A leather pattern usually includes the following information:
The lines on a pattern that indicate where you need to cut your leather, these are usually the outside borders of the pattern but may include internal cut-outs as well. In my patterns, cutting lines will always be indicated by solid black lines.
Internal lines on a pattern that indicates where two or more pieces are going to be joined by a line of stitching. On my digitized patterns, these lines are always indicated by dotted lines or lines of tiny circles.
Internal lines on a pattern that indicates where your leather will be folded and creased as you assemble your design. On my digitized patterns, fold lines are shown in red.
In order to sew, glue, or rivet leather pieces together we need to leave room between the sewing line or other attachment point and the edge of the leather. This space is called a seam allowance. The width of seam allowances can vary based on design and materials.
Black circles on my patterns show the placement of holes that need to be punched for rivets, snaps, buckles, etc.
Each pattern piece should be labeled with some information to identify it. This information should tell you: which piece of the pattern this is, what material it should be cut in (the main material of a design is called the “self,” and a secondary material is called the “contrast”), and how many copies of that piece should be cut.
(If you need to cut more than one copy of the exact same pattern piece for a design, you can usually just create one pattern piece in the paper, and then cut it out multiple times in leather.)
Step 2: Ease and Leather Thickness
When you are creating a pattern to fit around an object, you almost never use the exact dimensions of that object, instead, you need to add a little extra wiggle room or ease to your pattern dimensions.
The amount of ease you need to add often depends on the leather you are using. For thin leather, you only need to add a small amount of ease, for thick leather you need more. For flexible leather that has a little stretch to it, you can add less ease, for stiffer leather you will need more ease.
For example, say you want to design a flat two-piece pocket that will hold a single credit card, how big does your pocket pattern need to be? The credit card is 3 3/8″ x 2 1/8″. If you were to make the inside of the pocket exactly the dimensions of the card, it probably wouldn’t fit, or if you did manage to squeeze it in, you would have trouble getting it back out.
To add the right amount of ease, measure the thickness of your leather and add that amount of ease to each side of your pattern pieces, except on the side with the opening. If your leather is less than 1/16″ thick just use 1/16″ as your ease measurement. Let’s say we’re working with 1/8″ thick leather, so the final pieces should measure 3 1/2″ x 2 3/8″ along the sewing lines.
Ease on Folds
Now imagine you want to create the same pocket, but you want to do it with one folded piece of leather, not two separate pieces. If you take a piece of 1/8″ thick leather that is 6 3/4″ long (double the length of your credit card) and fold it in half, will it make a pocket deep enough to hold the card? No, it won’t.
Why? The inner depth of this folded pocket will be 1/8″ less than the length of the card because the thickness of the leather will take up that 1/8″ at the fold. Therefore, if you want the folded pocket to be as long as the card, you need to add 1/8″ to the pocket on each end for a total of 1/4″ of ease on that pattern piece.
Step 3: Patterning in 2 Dimensions
The basic goal in making most patterns is to figure out how to transform a flat material into something that will fit around a three-dimensional object. The more complex and three-dimensional the object, the more complicated your pattern will usually be. Here are some important things to keep in mind as you travel from two to three dimensions.
Patterning for Thickness Using Ease
Going back to our card pocket example, now say you wanted to make a two-piece pocket that would hold not just one card, but a stack of cards 1/2″ thick. How long and wide does a flat pocket need to be to accommodate this thickness?
If you are working with 1/8″ thick leather, first of all, you know you need to add 1/8″ ease on the sides and bottom of the card pocket.
To make room for the 1/2″ thickness of the stack, you also need to add half that thickness (1/4″) to the sides and bottom of the pattern. Since you are going to be using two pieces to create this pocket, the 1/4″ you add to each side will add up to the whole 1/2″ thickness you need when the pocket is put together. You don’t need to add that 1/4″ to the top of the pocket because it doesn’t need to bend around the sides of the stack of cards.
So when you’re creating a flat pocket for an object with some thickness, the general formula is this:
- Width of the pattern without seam allowance = width of object + thickness of object + (thickness of leather x2)
- Length of the pattern without seam allowance = height of object + 1/2 thickness of object + thickness of leather
As I mentioned before, the type of leather you are using can affect these measurements quite a bit. If your leather is really stiff you will have to add even more ease, if it’s a little stretchy, you can sometimes get away with less.
Unless you are trying to make something that is intentionally tight-fitting, it’s usually good to err on the side of more ease, rather than less. Some of this can really only be figured out by trial and error, but as you do more leather patterning, you will start to get a feel for it.
Step 4: Patterning in 3 Dimensions
Adding an extra room to a flat pocket like we just talked about is the most basic way to make room for objects with some thickness, but it really only works for relatively thin objects. To create designs with the built-in three-dimensional shapes you need to start creating patterns that are more than just two flat pieces of leather sewn together.
One of the best ways to do this is to add a gusset to your design. Let’s go back to our imaginary 1/2″ thick stack of cards and create a different kind of case for it.
We’ll start by taking the basic width and height of the cards and adding the 1/8″ ease for leather thickness to the sides and bottom, this is the size of the front and back pattern for your pocket before you add the seam allowance.
Instead of making the pocket bigger so it will fit around the 1/2″ thick stack of cards, we are going to add a side piece that accommodates the thickness of the stack. This side piece is called a gusset.
The length of the gusset pattern will be the length of the sides and base of the pocket combined (6 1/4″) + 1/4″ ease, and the width of the gusset pattern will be the stack depth of 1/2″ + 1/8″ ease.
To construct this case, these three pieces would be sewn together like this:
This is a basic gusset design, of which there are many variations. There are a lot of other ways to create three-dimensionality in cases, but most of them are based on the same basic concept: If you are creating a pattern for a three-dimensional object you usually need a seam where the angle of the object changes, the more seams you have, the more you can shape your design. There are also ways to create shape and volume with folding and pleating techniques. But for now, we are going to focus on seams.
Step 5: Designing a Simple Leather Bag
Now we are going to take all these concepts and use them to make a pattern for a simple leather bag. As you may have noticed, the patternmaking techniques I’ve been discussing center around the idea of making a case to hold an object.
Not every leather project involves encasing something, but many do, and learning how to make leather bags is a good way to practice basic leatherworking techniques.
The first step in my design process is almost always sketching. Well, actually, first I look for design inspiration by falling into a lot of Pinterest holes, but when I have a pretty good idea of what I want to make, I sketch. I usually start by making rough sketches of a few ideas, then I choose one design and do a more detailed technical sketch, with some dimensions.
When you are designing an accessory, like the bag we’re patterning, you need to think about its features and dimensions from an aesthetic standpoint and practical standpoint. A good thing to do is to define your constraints and work around them.
For the little bag, my constraints were: I wanted it to be big enough to hold my phone and a few other essential objects, but also small enough to be comfortable as either a belt pocket or an underarm pocket. I also wanted it to be constructed using sewing, and I wanted to keep the aesthetic of it fairly unisex.
With all that in mind, I ended up designing a small rectangular bag with a one-piece gusset, a flap, a strap and buckle closure, a small accordion pocket with a snap, and two strap loops to connect the whole thing to a single strap, belt or a shoulder harness.
When you are designing a bag like this, you aren’t literally designing it to fit precisely around a specific object as we were in the examples in the last two steps, but the same concept still applies.
So, to get an approximate size, I took a few measurements of objects like my phone, and the distance between my waist and my underarm, and came up with a set of dimensions based on these measurements. To start out with, all you really need is a height, width, and depth dimension for the bag when the flap is closed.
Step 6: The Pattern Draft
The first step in turning your design into a pattern is to create what I call a pattern draft. A pattern draft is a full-sized front, back, and (sometimes side view) technical drawing of your assembled final piece with all the correct measurements, it doesn’t necessarily show all the pattern pieces you need to create, but you will use it to determine the proportions and design elements, then trace pattern pieces from it.
To create a draft, first, draw a horizontal line near the bottom of your paper, then draw a perpendicular line coming up from the center of this line. This will be the centerline of your draft.
Now take your width and height measurements, and draw the basic outline of the bag from a front view around this centerline. I made my bag 5″ wide by 6″ tall. If you are working with paper and pencil, use a ruler to draw your lines, if you are working in Illustrator, use the rectangle or pencil tool.
Take a look at the proportions of this outline and decide if you like the size and shape, if you don’t, change it. Remember that the bag will end up slightly smaller than it appears here because of the ease that is taken up by the leather thickness.
I decided to make the top of my bag slightly narrower than the bottom (I took 1/8″ off each side) because I thought this created a nice shape. I also rounded the bottom corners because I liked the look and because curved edges will make it easier to sew in a one-piece gusset.