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  • Writer's pictureSew Retro

How to Read a Commercial Sewing Pattern - Part Two

Updated: Mar 8, 2020

Welcome to Part Two - of - How to Read, and Make Sense a Commercial Sewing Pattern.

Part two covers the straight of grain, what is it? and how do I find it? The fold line, what is it ? and how do I find it ? and how do I know which pattern pieces to place on the fold? How do I lengthen or shorten a pattern piece? and what are tailors's tacks? when do I use them ? and how do I make one ? Also included is a short video showing you how to make a tailors tack

What is the straight of grain?

The straight grain is the grain used most often in garments. The straight grain generally runs up the centre front and centre back of garments and up through the centre of sleeves and trouser legs.

If the garment is cut slightly off grain, (i.e. not on the straight of grain) this may cause sleeves or trouser legs to twist around the body.

You often find this in t-shirts because the fabric weave does not hold a solid grid pattern, making the fabric hard to cut correctly and causing the garment to be made up out of pieces which are off grain.

On areas such as waistbands which hold tension, you want the strongest thread to run around the body so you would cut your waistband patterns following the straight grain, i.e. parallel to the selvage. The selvage is the band of more tightly woven fabric that runs up either side of the fabric meterage as explained in part one.

If you imagine the fabric being woven on a weaving loom, then these are the edges where the thread turns back on itself to begin weaving the next row.

How do I find the straight of grain?

Fold your fabric in half selvage edges together. If your fabric is 150 cm wide when you have folded your selvage's edges together it will measure 75 cm.

If it is still 150 cm after folding the selvage's together you haven’t folded your fabric the correct way (unless your pattern tells other wise )You will know that you have folded your fabric the correct way by checking that you have half the width of your fabric.

Secure the selvage edges with a few pins so the two layers are kept together and the under layers do not slip while you measure to get on the straight of grain.

Lay your pattern pieces on to your fabric following the layout pattern which you will find in the envelope and explained in part one.

Using a tape measure and some pins

Measure from the top of the line with an arrow and marked “Grain Line”, to the selvage edge. On my pattern this measured 10 cm, put a pin in, at the arrow, to secure the pattern.

Move to the end of the grain line and measure 10 cm from the grain line to the selvage, YOU MAY NEED TO MOVE THE PATTERN A LITTLE TO GET THE CORRECT MEASUREMENT AT THE BOTTOM TO MATCH THE TOP (10 CM), when you are happy you have the same measurement at the top of the arrow and the bottom of the arrow, in my case 10 cm, secure again with a pin.

You are now on the correct gain, the straight of grain.

You will have to repeat this process with all remaining pattern pieces that need to be on the straight of grain. You next pattern piece will not necessary measure 10 cm because it maybe placed closer or further away from the selvage edge.

How do I lengthen or shorten my pattern?

On you pattern you will find two lines close together (as shown) marked “lengthen or shorten here.

To shorten by 5 cm (or any measurement) = measure down from the line and mark 5 cm at one end and 5 cm at the opposite end. Connect the marks with a pencil line. Fold your new line up to the original line and pin into place as shown.

You must make your adjustments on this line, you will not alter the shape or design of the pattern, in doing so on this line, however if you choose to alter the length of the skirt for example by cutting off 5 cm at the hem you may lose some of the shape or fullness of the design.

How do I lengthen a pattern?

Using the same line as shown above, with paper scissors cut along the line,

tape a piece of paper onto the line, add an equal amount as shown (I have added 5 cm) mark a line

then tape the remaining pattern piece to the line.

What is the fold line?

Went you fold your fabric in half, selvage edge to selvage edge, you automatically create the fold line, it is opposite the two selvage edges when you have folded your fabric as show.

How do I know if my pattern piece needs to be placed on the fold line?

A fold line may be marked with just the words “FOLD LINE” or a boxed arrow (as shown ) and indicates that this edge of the pattern piece should be placed along the folded edge of the fabric.

You do not need to measure any of the pattern pieces marked “centre back on fold “ or “fold line” for example because you are automatically on the straight of grain as you pinned you selvage edges together before you started to pin the pattern onto the fabric.

Very occasionally (so occasionally I could not find a pattern piece to shown you an example)

You may find a pattern piece marked ----------- FOLD LINE ------------ with the broken dash line (as shown) in the middle of a pattern piece, normally on a waist band.

This is NOT the fold line as explained above, but a guide as to when you have cut out the pattern piece in fabric where to fold the fabric in half, to make the front and back of the waist band.

Instead of cutting a two piece waist band you are instructed to cut one piece of fabric on the straight of grain with the arrow showing you the direction of the grain line and fold it in half.

What are tailors’ tacks?

Tailor’s tacks are used for transferring the marking from the pattern onto the fabric i.e., the bust dart or the position of a patch pocket. If you think of using a pen to write a shopping list, this is the same just using tread that is easily removable once you have pined and sewn on the patch pocket or sewn the dart.

How are they marked on my pattern?

They are usually marked with a circle as shown for the bust, waist, back and shoulder darts. They will be marked with a X for the position of the button, and a line as shown for the position and length of the buttonhole.

How do I make them?

You will need a hand sewing needle and contrast thread.

Thread the needle and have your thread double but no knot at the end.

Push your needle through the middle of the circle and through both layers of fabric.

Bring the needle back through the work.

Go back in and make a loop

Come out and cut the thread.

Repeat until you have transferred all the relevant pattern markings. When you want to remove the pattern from the fabric, remove your pins, hold onto the thread, and give the pattern a gentle tug. You will leave the thread in place, gently pull the two pieces of fabric apart and snip your thread, leaving you the markings on the left side and the right side.

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