How to use a sewing pattern? – 5 basic things to know about sewing patterns

How to use a sewing pattern? – 5 basic things to know about sewing patterns
09/09/2019 Cami

Hello everyone!

You would like to start sewing clothes but buying and using sewing patterns is daunting? It is absolutely normal… Read these 5 tips to understand how sewing patterns work.

When I started sewing, after a first attempt to use a sewing pattern (which I didn’t understand at all), I decided to sew a few garments without pattern because I thought I would be better off without. Basically I cut garment pieces directly onto fabric. Honestly the clothes I ended up with were not so bad, but what a pain and a waste of time…and then I took a sewing course and understood a few basics that I was missing before: it was as if a whole new world had opened up for me. So I’m sharing these few game changer tips with you today. 

1. What is a sewing pattern and why do I need this?

To start with, a sewing pattern is a guide to sew a garment shape at a desired size. It includes a set of flat pieces drawn on paper helping to cut fabric and thus sew a garment. In general, it includes sewing instructions to assemble these pieces together in the right order and following a certain methodology.

For instance, the sewing pattern of a simple t-shirt includes 4 pieces: the front, the back, the sleeve and the neck band. It explains that you need to cut 1 front piece on the fold of the fabric, 1 back piece on the fold of the fabric, 2 sleeve pieces and one collar band. Finally it tells you the steps to go through to sew these pieces together. 

Sewing pattern pieces of a t-shirt

Sewing patterns are in several sizes, so the pattern pieces are shown in the available sizes on paper. Generally, sizes are drawn by lines of different styles in a nested way, so that you can cut the size you need easily. 

Sizing lines on a sewing pattern

2. The sewing pattern types you can buy

Nowadays, we can find 2 main formats of patterns for sale:

  • Paper patterns: this is the traditional type. The pattern is printed on a large piece of paper and the instructions are printed too. Generally, the biggest brands offer the patterns on silk paper (very expensive to print) and younger / independant brands offer the patterns on heavier paper, close to the one we find in our home printers.

Paper sewing patterns

  • Digital / PDF patterns: there are more and more patterns available in PDF format. When you buy a pattern in PDF format, you can either print it at home on A4/US letter sheets of paper or at a copy shop on A0 sheets. If you print at home, you need to assemble the pages with magic tape which is ok when there are not too many pages, but can be a pain if there are more than 40 pages (in my opinion)…For digital patterns, instructions are also in PDF, and you don’t necessarily have to print them, you can follow them on your device. 

PDF patterns, stored in ring binders

3. What are seam allowances?

Sewing patterns can include seam allowances or not. They are essential to sew a garment. They are edges added to the garment pieces, often 1cm or 1.5cm, allowing to sew the pieces together at this distance to achieve the correct size. 

Seam allowances in red

When sewing the pieces together, you only have to follow the guide on your sewing machine.

Machine seam allowance guides are on the right of the needle.

Once the garment is sewn, most seam allowances are inside the garment (unless they are used as decorative elements). In any case, without seam allowances, a garment cannot be sewn.

Seam viewed from outside the garment

Seam viewed from inside, with seam allowances in red

Sewing patterns tells you if seam allowances are included or not: 

  • If they are included, then no problem, you can use the pattern as such to cut the fabric. Seam allowances are not shown on the pattern, they are included in what is drawn.
  • If on the contrary they are not included, you will have to trace the pattern pieces on a separate paper and add the seam allowances yourself, or you will have to add them by tracing them directly on the fabric around the pattern. Personally I don’t like patterns where seam allowances are not included, it feels like an unfinished product and it is prone to errors.

4. How to cut a sewing pattern?

There are a few schools regarding how to cut a pattern:

  • If you are too impatient like me, you can cut the pattern pieces directly on the paper.

  • If you would prefer to preserve the original pattern, you will prefer to trace the pattern on another piece of paper and cut the pattern on there.

In a few cases, it is not possible to cut the pattern directly in the original pattern, and you have to trace it on another paper first: 

  • When the seam allowances are not included, as mentioned in the previous chapter. 
  • When the pattern pieces overlap or when they are printed on both sides of the paper. It is often the case in books and magazines for paper saving purpose.

Pattern pieces overlapping

Once you know how to cut, you take your scissors and cut all the necessary pattern pieces.

5. How to cut fabric from a sewing pattern? 

A sewing pattern indicates how to cut the fabric and what to cut in the fabric, thanks to fabric layouts. For the best results, just follow the layouts.

Cutting layout

In most cases, and when the garment is symmetrical, you will have to fold the fabric lengthwise and right sides together, putting the selvedges (edges of the fabric) together, in order to cut the fabric on 2 layers. 

Folded fabric with pattern pieces on top

There are exceptions though: 

  • Some pieces require to be cut once;
  • Some pieces have to be cut on the bias; 
  • When the fabric is very thin or unstable or both (the worst), it’s better to cut on one layer; 
  • In order to save fabric or if you want to make fabric print matching, you can decide to cut some pieces on one layer (this is something I do a lot!). 

Once we know how the pattern pieces have to be laid out on the fabric, they have to be pinned onto the fabric and fabric can be cut all around them.


So, what are you waiting for to use some sewing patterns? 


Do you have any questions about sewing patterns? Don’t hesitate to leave a comment below!