With rotary cutting and accurate machine sewing four and ninepatch blocks are a breeze!
With rotary cutting and accurate machine sewing four and ninepatch blocks are a breeze

If sewing by machine, there a number of techniques you can use to sew patches together quickly and precisely

One speed technique is called chain sewing and is ideal when you are building up smaller units of a block, such as squares or triangles. The patches for machine piecing are cut accurately, using a rotary cutter, with the 1/4in seam allowance included. The seamline is measured 1/4in from the cut edge, although it is not marked.

Checking 1/4in seams
Checking 1/4in seams

Checking your 1/4in seam

  1. Cut 5 strips of fabric 1 1/2in x 6in (or longer). Choose two fabrics so you get stripes when they are sewn together.
  2. Line up the first two fabrics and sew with a 1/4in seam. Press and then add the next strips in the same way.
  3. Give a final press and lay under your ruler to check. Is it straight? Does it measure 5 1/2in by 6in? If it is much narrower or wider, this will have an impact on your piecing.

Tiny variations repeated over many seams can have a major impact on the final block or quilt. Another problem is that it can also be curved like a banana as it is harder to piece accurately at the start and end of each row. (One solution is to start to sew off a small scrap of fabric. This gives the teeth something to start on and also stops the corners getting chewed in the feed dogs.) Do not worry if your sample is not straight or the right size. Cut some more strips and have another go.

There is no need to tack before machine stitching, and in the initial stages, no need to pin either. Feed pairs of patches through, one after another, not cutting the threads in between them. This saves time and thread and because you carry a line of chain-sewn little "flags" to the iron, there is less chance of losing some on the way.

TIP! Work efficiently - sew all the left sides with chain sewing, then turn the whole set around and sew all the other sides.

Alternate pressed seams to reduce bulk
Alternate pressed seams to reduce bulk
TIP! You can make your own seam guide if you don't have a 1/4in foot. Place a ruler with the 1/4in line under the needle and use the masking tape along the edge of the ruler to make a guide for the fabric. If you stick two or three layers on top of each other you get a good edge to run the fabric alongside.
Chain sewing patches
Chain sewing patches

Pressing

Seams are pressed to one side, not open. Press towards the darker fabric, towards the edge of the block, or away from where the quilting stitches will be. Pressing means picking the iron up and down, not sweeping it across the fabric. First press the seam that you have sewn with both fabrics exactly as you have sewed them. This sets the stitches into the fabrics. Then hold the darker fabric on the top and fold back as you press the iron down, this presses the seam allowance toward the dark fabric. Press seam allowances of adjacent rows in opposite directions to reduce bulk where they cross. Give a final press on the rightside to avoid any little pleats which can spoil the accuracy of patches.

Careful pinning helps seams to match
Careful pinning helps seams to match

Matching seams and accuracy

To match seams when joining rows, pin carefully with pins at right angles to the seam to be sewn, and along the lines of the seams to be matched.

Don't worry too much if your patches don't match and you lose triangle points. We all improve with practise. Constant unpicking of seams and re-sewing is demoralising, plus it weakens the fabrics.

Quick pieced four and nine patches

With rotary cutting and accurate machine sewing four and nine patch blocks are a breeze. Fat quarters of fabric are idea, so that you can cut long strips with the rotary cutter. Include the seam allowance when cutting strips.

Quick four patch blocks
Quick four patch blocks
  1. Sew two strips for a four patch or three strips in two combinations for a nine patch. Press. Cut at right angles using the same measurements as above.
  2. Rotate one of the sewn units for a four patch and re-sew. For a nine patch, use two of one unit and one of the other. Make sure that the corners match as you sew, by accurately pinning. Press again.
Quick nine patch blocks
Quick nine patch blocks

Finished size of square + 1/4in + 1/4in = width of strip to be cut

eg a 2in square: 2 + 1/4in + 1/4in = 2 1/2in strip to be cut

This will give a 4in finished four patch or 6in finished nine patch.

Half and quarter square triangles

These units are part of many patchwork blocks. They are quick and accurate when sewn by machine, Because of the method of sewing, cutting and re-sewing, you will need to allow an extra seam allowance of 7/8in, to the finished measurement you require.

Half square triangles
Half square triangles
  1. For a finished 3in unit cut two strips 3 7/8in wide from two fabrics. From both strips cut 3 7/8in squares.
  2. Take two squares,one of each fabric and pair them up RS together. Draw a diagonal line, corner to corner, on the lightest fabric. Sew either side of the line with a scant seam allowance. Note: if your sewing machine foot isn't the required width, you can draw the sewing lines on the fabric instead. Try to sew just inside the line, on the seam allowance side.
  3. Cut apart on the diagonal line. Press the half-square triangle open, with the seam to the darker side. Cut off the "ears", the sticking out bits of seam allowance, in line with the sides of the square.
  4. For quarter square triangles, pair up the half square triangles RS together, with opposing colours placed together.Repeat the marking and sewing from Step 2 and cut apart.
Quarter square triangles
Quarter square triangles

TIP! Clear perspex sewing table extensions spread the weight of larger pieces of fabric and quilts when sewing. If you place a mirror under the table, in front of the sewing machine, it gives a splendid view of what is happening underneath. A quick glance down just as that awkward seam comes up in front of the presser foot, ensures that all the pieces are lying just as needed for a perfectly intersecting seam. You can also check that the lower fabric is in fact in line with the upper when sewing 1/4in seams with poorly contrasted fabric.

First published in Patchwork Basics 2002