A Quilting Blog

Named for my ancestor,
Thankful Day

Tuesday, February 22, 2011

Do the Math!!

I heard a dear friend say the other day that she majored in her degree field because she wanted to avoid Math.  Actually I often see pained expressions and sometimes terror in the people's faces when the word "Math" is uttered.   And I do understand.  For some people it comes easily and for many of the rest of us it takes work and personal focus.  Math is for the mind like physical exercise is for the body.  At first it hurts and we don't want to do it.  But once you get over the initial hump - it gets easier.

I am not talking about anything more than simple math.  It comes in handy every day.  Doubling a recipe, or simplifying it ( why write 3 teaspoons when that equals 1 tablespoon; or 4 tablespoons when that equals 1/4 cup?). 

In quilting it makes all the difference in the world.

Yesterday I was working  a particular block pattern  - that was made up of 4 equal units.  Each unit was made of 4 quarter-square triangles, of which 1 was whole and 3 were pieced from templates.  However, when the blasted thing didn't fit together correctly - I started measuring - and sure enough the templates weren't sized correctly.  The designer didn't do his/her math (or obviously make the pattern as written).

Here are some ways to double check yourself and your templates:
Half square triangles: should equal the finished size plus 7/8 inch
Quarter square triangles:  should equal the finished size plus 1 1/4 inches

For example:
If a 6 inch square is made up of 2 triangle pieces, your pattern should call for you to cut a 6 7/8 inch square and then cut once on the diagonal to make 2 triangles. This is called a half square triangle (or you put 2 squares together and sew on either side of the diagonal to make 2 HSTs at once). These cut pieces will finish,when sewn together,  into a 6 inch square.

If a 6 inch square is made up of 4 quarter square triangles (picture a square divided twice diagonally), the long side of each of those quarter square triangles should measure 1 1/4 inches longer than the desired finished size for the side of the square.  To cut the triangles pieces for those, you would first cut a square 7 1/4 inches and then cut again diagonally twice (like an X ) to produce 4 equal triangles.

So the problem I had was that on of the 4 triangles in each block was from a solid piece of fabric.  So the instructions said:  cut a 7 1/4 inch square and then cut diagonally twice to make 4 triangles, 1 to be used in each block unit.  (Here that tells me that each unit should finish out at 6 inches). 

Next, there was some strip piecing and fancy cutting involved with provided templates to make the other 3 quarter square triangle parts of each unit.  But a measurment of the templates showed them to be incorrect since their long sides only equaled 6 7/8 inches and not the 7 1/4 they should have been.

Wasted effort?? NOPE!!  With a little trimming and the addition of a block border this 11 1/4 inch block will recover into it's rightful 12 1/2 inches just fine!!!

No comments:

Post a Comment