From Marti Michell Quilting Blog: Chart 10: Parallelograms 101 and Jenny, Block #45 in the Farmer's Wife 1930s Sew Along

Parallelogram: Any 4-sided shape with 2 pairs of opposite parallel and equal length sides. The opposite corners are also matching angles.

A parallelogram is not a square, but a square is a parallelogram. In addition, diamonds are parallelograms with 4 equal sides.

Right about here, you may be muttering that if you had known you were going to make a quilt, you would have paid attention in geometry class! I'd like to help you become more comfortable with parallelograms and other parts of quilt geometry.

One frequently used quilter's parallelogram is created by joining two 45-degree right angle triangles, or what quilters typically call half-square triangles (HSTs). They can be joined with the straight grain on the legs or on the hypotenuse, depending on the block design.

Jenny needs the straight grain on the hypotenuse. As you follow the conversion chart to make the Jenny block, you will learn to cut a parallelogram with a triangle template and eliminate the seam. You might ask, "If you can just sew 2 triangles together to make a parallelogram, why would you bother to cut a one-piece parallelogram?"

Because you want to…

eliminate extra seams, which reduces bulk and work.
protect the integrity of fabric designs. No one wants a seam in the middle of a stripe or other directional print, most large prints or fussy-cut designs.
turn your patchwork skills up a notch!

Jenny is the first block in the sew-along that includes parallelograms. However, before you finish this quilt, you will be quite familiar with parallelograms! Parallelograms are directional. Interestingly in this block, they all point the same way, to the upper right. Unless you are working with batiks, solids or hand dyes, once you cut a parallelogram, it cannot be turned to point in the other direction -- so all of Jenny's parallelograms are cut with the fabric right side up.

What if?

What if you forgot to cut with the fabrics right side up?

If both strips were right side down, the design will just spin in the other direction. That's fine!
If the strips were right or wrong sides together, you will get mirror image parallelograms and you will need to cut again. It is quite common in quilt blocks for pairs of parallelograms to be mirror image units, but in this block they are not. However, when we get to making blocks with mirror image parallelograms, you will already know how to do it! :)

Introducing the Half-on / Half-off Cutting Trick

Our Jenny conversion chart illustrates placing the template half-on, half-off the end of the strip to begin cutting the first parallelogram for right-handed cutting. If you are left-handed, start at the right end of the strip and position the triangle template the same way, half-on, half-off. Starting this way is efficient; it means cutting each triangle from the strip will be easy and comfortable.

Our cutting techniques are aimed at keeping your cutting hand and rotary cutter properly positioned in relationship to the acrylic tools. That is, typically you will cut more accurately if your hand and rotary cutter are to the right of the acrylic tool if you are right-handed, and to the left of the acrylic tool if you are left-handed.

From Marti Michell templates can perform a lot of cutting tricks, including cutting a shape for which there is no template -- like a parallelogram -- and cutting it the size you need. Some of our methods may seem awkward at first because you are not accustomed to them, but as we sew along, I think you will recognize the benefits of cutting certain shapes with a cutting trick.