## Quilters’ Math

Deer in the headlights. That’s me when I try to fit my head around calculating the size of a square I need to cut to make corner and setting triangles for quilts set on point. But things are looking up, thanks to guild member Connie Huston, who took us through easy steps to solve the three most common calculations needed for quilting! You can click on the accompanying photos to print or save them for yourselves.

Calc #1: Enlarging and Reducing Blocks: How do I change the size of an applique or block pattern to the size I need? This easy rule will keep the same proportions to enlarge or reduce the size of the figure. You will get a number that you can take to a copying machine so your new pattern will be exactly the size you need.

“Start with what you want, divide by what you have.” That’s all there is to getting the percent to enlarge or decrease a block. If you want a 6″ finished block and you have a pattern for an 8″ finished block, 6/8=.75, or 75% of your original block. Put the original block on a copying machine and set it to 75% (or .75) to get what you want! When you are enlarging a block, do the same thing, but expect a number greater then 1. In other words, 150% to go from an 8″ block to a 12″ block.

Calc #2 Corner Triangles: Blocks set on point make a nice contrast to our usual row quilts. But how do you figure the size of square to cut so you make the most efficient use of your fabric? In other words, how do you make a Half Square Triangle (HST) of the proper size?

Having fallen into the trap of cutting a square the same size of my other blocks, then cutting it diagonally and discovering that the resulting triangles were too small, I was ready for the next step in beefing up my math mind.

The problem can be avoided if you add a seam allowance to the finished size of the block. Remember the “7/8’s Rule” when making HSTs. Take the FINISHED size of the blocks, and add 7/8″ to make up for what is lost in cutting and then piecing the diagonal edge.

So if you want a triangle to piece to a 4″ finished block, make the square 4 7/8″ and cut it on the diagonal. (The photo uses a 3″ finished block as an example.) The resulting HST will be used as the setting triangle in the corners of your on-point quilt. You will need to cut two squares to make the four HST corners.

A small problem occurs when a square is cut into the two HST triangles. The long edge is cut on the bias, which promotes stretching when the triangle is pieced with the other blocks. BEFORE stitching, heavily starch and press straight up and down on the bias edge to reduce the stretching problem. Fortunately, HSTs produce triangles with grain-of-fabric edges along the outside of the quilt top, which is what you want to avoid stretched out “kitty ears” at the corners. (OK, “puppy ears” for you dog lovers.)

Calc #3 Side Setting Triangles: To fill in the sides of the on-point quilt with no waste fabric and no-stretch grain-of-fabric diagonals, you will want to make Quarter Square Triangles, or “QSTs”. Again, the trick is to add enough to account for seam allowances. For that, you need to use the “1.41 Rule.”

Multiply the FINISHED size of the other blocks by 1.41 and round to the closest 1/8″. Then add enough for seam allowances. You will cut both diagonals of the resulting square, resulting in four QSTs to piece along the sides, top and bottom.

As an example, if you have FINISHED blocks of 8″, you will want to cut a square of 8 x 1.41 or 11.28″, plus seam allowance. Round 11.28 to 11.25″ and add another 1.25″ for the seam allowance. The square you need to cut is 12 1/2″. Of course, if you have a different size of blocks, you will not use 8″ to start!

Cut along both diagonals of the square. Again, starch the bias edges (the two short sides in QSTs) to reduce stretching when your triangles are pieced to the other blocks. Happily, the diagonal edge of each QST is on the grain of fabric, which doesn’t stretch much, just what you want on the outside of the quilt top.

To determine the number of squares you will need to cut into QSTs for the setting triangles, count how many side triangles your quilt top needs (don’t include the four corner triangles) and divide by four.

Thank you, Connie for showing us “mathphobes” how to make these relatively simple calculations! It was easier than we feared!

## Fall Quilting Retreat and Other Matters

The upcoming retreat will be held Wednesday, September 25, 9 AM to 4:PM at the Episcopal Church in Gallipolis. Takeout lunch is planned. Bring your UFOs, $5 and something for the church’s food pantry. Watch for a separate post with pictures from the retreat!

Ronald McDonald quilts for babies, children or youth are due at the November meeting. So are the “Three Crayon Challenge” blocks, says Challenge Mistress Mary P.

The annual CEOS quilt show will be October 5 and 6 with quilts being accepted on October 4. All members are urged to enter quilts in the show.

The program for the October meeting will be transferring photos to fabric. Members are invited to bring any projects they have done using photos to the meeting. Food will be in “Octoberfest” tradition! Bring your lederhosen and dirndl skirts–maybe we can polka after the meeting!

## Show-N-Tell

The most unusual show-n-tell was a magazine article Sakine brought in about traditional geometric paintings in the parlors of old-style homes in Saudi Arabia. Watch for closeups of the pages for rooms with built in ledges for seating cushions, with elaborate designs around the walls. The paintings were originally done with natural mineral and vegetable paints, the work of skilled women.

These paintings and the artists who produce them are national treasures, and efforts are being made to keep the distinctive craft alive. For instance, the motifs are now showing up in pottery and other decorative items in the market places. Some of the Saudi royal families have commissioned one of the remaining artists to paint rooms in their magnificent homes.

- Kay R, circle of leaf quilt, strip tote bag, child theme wall hanging;
- Mary P, Hawaiian Appliqué square, baby quilt;
- Mary B, hanging kitchen towel, ;
- Betty R, tea towel made by Frankie Bumgarner made for Betty’s birthday
- Mollie Y, barn block quilt with QR code;
- Nina B, challenge quilt, Visions of WV quilt top pieced by Abby Hutson;
- Sakine D, cancer totes, pictures of Saudi quilt paintings;
- Connie C, Christmas quilt, yorganic scarf

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