The Quarter Square
Triangle
The quarter inch triangle is a
very simple block that will help to illustrate the BIG
difference between the quarter square triangle, and the
half square
triangle.
If you look at the above
picture, you will see that the long side of the triangle (the
hypotenuse) is on the straight grain of the fabric.
When you have an edge on the
bias, it will not be stable. It will want to stretch and
distort, and even that 1/4-inch seam allowance you have perfected is
not going to help you!
Let's take a look at how the
quarter square triangle comes about.
First of all, here is some math
for you to remember.
If you want to make a
"finished block", add 1 1/4 inch to the size of the squares you are
going to use to make your quarter square triangles. For
instance, if you want your Quarter Square Triangles to end up at 6
inches finished, you would begin this process with two 7 1/4 inch
squares.
If you want
to make a "raw block" (the size of the block before sewn to other
fabric) , add 3/4 of an inch to the square size for the seam
allowance.
In the picture above, I wanted
the finished block to end up at 7 1/2 inches. So I cut two
squares at 8 3/4 inches.
Next
you put your two blocks right sides together, and draw a diagonal
line from corner to corner. This starts out the same way you make
half square
triangles.
Again, sew 1/4 inch away from
both sides of your mark, and then cut down the drawn line. Press towards the darker
fabric.
You now have two half square
triangles. Here is how you turn them into quarter square
triangles.
Take the two pieces, and put them right sides
together. However, this time you have to pay attention to the
colors. When you put them right sides together, alternate the
colors. In this example, the black would be under the
raspberry color on one side, and the raspberry color under the black
on the other side.
Draw another diagonal line -
this time going from right to left, or opposite of however you did
it the time before.
Again, sew 1/4 inch on
both sides of your line, and then again cut them apart on your
marked line. Press towards the darker
fabric.
When you open your triangle, it
should look like the picture at the top of the page. (You will
have two of them)
If you study these pictures,
you can see how the bias moves on a half square triangle from the
long edge to the short edges with the second step.
When you put squares together
in what is called a "diagonal set" you will need a triangle
on the end of each row. This will always be a quarter square triangle so
that the edge of the fabric is stable.
If it very important to
understand the difference in these triangles. If you are
following a pattern, it will tell you how to cut these triangles.
However, when you start putting things together on your own, you
must pay attention to the grain and use the correct triangle.
Block size -
9 1/2 x 9 1/2
inches
