Make a
Half Square Triangle Block

The No-Math Way: Technique #5 - Use a specialty ruler

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To make a half square triangle block in Technique #1, we used our everyday ruler and had to remember to add 7/8" or more to the finished size of the block to cut our initial squares.

With a specialty ruler, like the Fons and Porter Half and Quarter Square Triangle ruler (that we use in this example) or the Easy Angle Triangle Ruler, the only thing you need to remember is the size of your unfinished block.

The ruler has a special feature that allows you to cut narrower strips and saves fabric.

This feature also means there's only one dog ear to trim saving you time.

Making half square triangles with specialty rulers

If you frequently work with Jelly Rolls or Honey Buns (2-1/2" or 1-1/2" wide precut fabric packs), these specialty rulers are PERFECT for you. That's because the ruler is designed so you can cut half square triangles from the same strips as your squares and rectangles.

Pros:

No magic number to remember
No paper to remove
Less waste—blocks are cut from the same size strip as other block components
Only one dog ear to trim
Perfect for use with precut strips because you can use the same strip for cutting several shapes.

Cons:

Yet another ruler to buy and store
Size is limited by the size of the specialty ruler

The Rulers

For this technique you need a ruler marked especially for making half square triangles. These are two that I use and own.

Fons and Porter Half and Quarter Triangle Ruler available from Amazon.com

Click here to purchase from Amazon.com

The Fons and Porter Half and Quarter Ruler can be used for both half (4" finished) and quarter square triangles.

Easy Angle Triangle Ruler available from Amazon.com

Click here to purchase
from Amazon.com

The Easy Angle comes in three sizes:

Up to 4" finished

Up to 6" finished(Shown to the left)

Up to 10" finished

Which do I prefer?

If you are thinking about purchasing this ruler, my advice is to buy the Fons and Porter Half and Quarter Ruler.

It's two—well actually three—rulers in one. You can use it for cutting half and quarter square triangle units AND Flying Geese patches.

Less to buy.

Less to store.

The only thing you have to watch out for, is because of the dual use, there are more markings on it.

Each technique is illustrated and diagrammed right on the ruler to make it easy.

The Technique

For this example we are making a 3" finished (3-1/2" unfinished) half square triangle unit with the Fons and Porter Half and Quarter ruler.

For HSTs, as you look at this ruler with the yellow triangle pointing up, the numbers in the yellow circles that sit on black and yellow lines indicate the finished size of the HSTs. Cut your strips equal to the the black number just above the black/yellow line at the left edge of the ruler.

No 7/8" to remember, just nice easy numbers!

Step 1

Cut a strip of fabric from each of two contrasting fabrics whose width is equal to the unfinished size of the block. Our strips are 3-1/2" wide (from fat quarters).

Helpful Hint

While the two strips are shown separate in the photo below, to save time, layer the two fabrics right sides together AND THEN cut your strips. They are then ready for sub-cutting into half square triangle patches without having to line up the edges.

Sweet!

Step 2

Align the '3' line (see the red circle) of the ruler along the bottom edge of the strip. The bottom edge of the top yellow triangle should be even with the top edge of the strip.

It's the positioning of this yellow triangle that saves the fabric--using traditional techniques we'd be cutting strips that are 3-7/8" wide...a nice fabric savings if you're making lots of blocks or using pre-cut strips cut to standard widths.