Seams (the lines on which you sew) are indicated by a solid line. The color of the line indicates the fabric type of the pattern piece:
Seam allowance is indicated by a dashed line, that has the same width and color as the seam they belong to:
Note that the corners of the seam allowance are trimmed, and not extended:
Some patterns may have other lines on them, there are 4 additional styles:
They might be used by patterns designers to add additional info, depending on the context.
Cut-on-fold indicators look similar, but point towards the line on which the fabric should be folded:
There are two types of notches. The default notch is a blue dot in a blue circle.
An alternative style shows a red cross in a red circle. This style is used to indicate the back of a garment. For example, on a sleevecap you may see a blue and a red notch. This way you know which side of the sleevecap is the front (the one with the blue notch).
Why we chose these notches
In electromagnetism, a ⊙ symbol is used to indicate a flow of current coming towards you (to the front), whereas ⊗ is used for a current moving away from you (to the back).
You can also think of an arrow. When an arrow flies towards you, you see its tip (⊙). When an arrow flies away from you, you see its fletches (⊗).
Buttons and buttonholes may come in different sizes, but always have the same shaped that represents how they look like in real life:
Snaps have a stud and socket part, and also look like the real thing:
When you opt for a paperless pattern, your pattern will come with dimensions:
Some patterns use dimension to indicate the full size of a pattern piece. This typically happens when a part is a mere rectangle and printing, as a way to save paper.
So when a pattern includes a dimension, make sure to pay attention to it.
The scale box allows you to verify that your pattern was printed to the correct scale:
To verify the printed size, you can first only print the page that has the scale box on it.
Each pattern piece has a title that tells you the number and name of the piece, as well as the pattern name:
When you generate a pattern on freesewing.org, the title will also include the name of the person the pattern was made for.
Some (or all) pattern pieces may also include the FreeSewing logo. The logo has no special meaning, it’s just branding.
Designers can, if they so choose, override the default line widths or set a specific stroke. They might do that to add additional info, like where to fold a pattern, or the outline of where a pocket would go.
For reference, here are the different available line widths:
And these are the different stroke styles: