Sewing pattern symbols are used to help you achieve accurate results when cutting, matching pieces, and sewing. They do vary slightly between designers but these are some universally used sewing symbols to help you get started.

SEWING PATTERN SYMBOLS
This week we are learning about cutting and marking fabric in the how to sew tutorials.
What are the most common sewing pattern symbols?
The most common sewing pattern symbols are
- Grain lines
- Fold lines
- Notches
- Button and buttonholes
- Dots, squares and symbol markings
- Adjustment lines to lengthen or shorten
- Stitching lines
- Darts
1. Grain lines
These double-ended arrows tell you to place the pattern piece parallel to the selvage. Measure from the top and bottom of the arrow and ensure they are equal distances from the selvage. For example, if the top of the arrow is 4 inches (10cm) from the selvage, the bottom of the arrow should also be 4 inches from the selvage.
Further Reading: What is Selvage.
2. Fold lines
This symbol rectangular sewing pattern symbol has one open side and means place on the fold. Place your pattern piece on the folded edge of the fabric, making sure the selvages are even on the other side. If you are adding seam allowances, you do not add any to fold lines. Cutting on the fold ensures your pieces are completely symmetrical and is often a good way to minimize fabric consumption.
Further Reading: How to Cut Fabric
3. Notches
What do the triangles mean on sewing patterns?
Triangles and diamonds are called notches and indicate you need to mark these points to enable you to match up the pattern when sewing. Notches can be single, double and colored, or open.
I always recommend you cut outwards but this is a personal preference. See my article on how to cut notches for more information.
4. Button and Buttonholes
Indicate button and buttonhole positions. The sewing pattern symbols of a long bar with vertical ends represent the size and position of the buttonhole and a cross is common for the button sewing position.
Read my articles on sewing buttonholes by machine and how to sew a button.
5. Dots, Squares and Shapes
All shapes need to be transferred onto your fabric and are used for matching up pattern pieces and adding details. You can transfer with tailors tacks, chalk, or a removable pen. See my blog articles on marking tools in sewing and transferring markings.
6. Adjustment Lines (Lengthen or shorten lines)
These are double lines that are normally accompanied by the words lengthen or shorten here. These are quite common in sewing leotards and pants where length matters.
7. Stitching lines
Stitching lines are not generally found on multi-sized patterns but on single-sized patterns they are represented by dotted lines. Generally, there is no need to transfer these lines onto your fabric.
8. Darts
Shown as a dotted triangle or diamond, these show you where to stitch to add shape in areas such as the bust and waist. (Read how to sew darts)
How to Cut Sewing Pattern Symbols
Now you know all about sewing pattern symbols and their meaning, it is time to start learning how to cut fabric. This article will show you how to fold your fabric, place it on the grain, and how to cut it accurately.
If you are a beginner and just building your sewing kit, then you can read about cutting tools in sewing and which are the best ones to purchase.
For those of you that are going to be quilting or cutting a lot of straight edges, learning how to use a rotary cutter may also help.
If you have come across any unusual sewing pattern symbols? Please share below.
Etim
Nice
Treasurie
All designers use different notations but I imagine the B is referring to an option number. Many patterns have several options and will need different pieces cut.
Linda Clapper
I have a question: I noticed when looking at the front of the pattern there are letters and then sizes ex. B5 (6,8,10,12) .What does this mean and how does this apply to sizing a pattern for me. Thank you f or your response.
Treasurie
RST - means right sides together SA - means seam allowance
Ranae
What does RST &SA mean in directions in making a pillow?
Jenny
You are very helpful. Thank you so much.
givo
i like this page
Treasurie
Hi Grace, Sorry I couldn't say without seeing their pattern pieces and layout. I did google the pattern but there was no layout in the listing. Normally in New Look patterns, there will be a pattern layout section showing you how to lay out the pieces. It is normally on the first page of the internal instructions. Have a close look at that and hopefully it will solve the problem. In general, pockets are not cut on the fold but they may have some special method they are using.
Grace Paynter
HELP! I am trying to sew a pair of pants using New Look pattern #6005. I do not understand how to lay out pattern piece #2 for front yoke and pocket A,B. The pattern has a fold line that has nothing to do with the fold line of the fabric and the pattern piece extends past the fold line of the fabric. I hope to hear from you soon.
Basssey F. E
Thanks, it really made me understand more.