kaylfordsollimo

Retired math teacher answer: taking your 48"x 60", then adding 3" on all sides (plus 1" for the 1/2" piecing seam he allows) gives Wq = 55", Lq = 66", and Wf = 43". Now using those values in Mr. Flynn's formula, the length of fabric (Lq) needed is 92" (~2.5 yds). The diagonal seam will, of course, have the danger of stretching due to the bias edges. I highly recommend a good starch and pressing before cutting the backing. I've done with and without - with is worth the time and effort, believe me. I used to use this exact problem in geometry classes for "when am I ever going to use this in real life, Mrs. S" questions?

par4theday

While on this subject, has anyone used this method with Miinkee on the back. I would imagine that it would be very difficult to get a good diagonal seam with Minkee, but has anyone tryed it?

Jenny3244

Sparrow Quilt Co. https://www.youtube.com/watch?v=4ebZG0CReGM She used the fusible tape (usually used for piecing batting pieces together from scraps) down the diagonal, then cut (tape stabilizes the bias on stretchy fabrics). That should solve the minky issue (unless you can't iron minky?)

HouseDragon

All the links before Jenny's post have expired.

Donas

I found John's calculator:
https://www.flynnquilt.com/free-lessons.htm

Thank goodness,
Donna

L'il Chickadee

Thank you for the link to the John Flynn website and formula. We did the diagonal cut method to make my design wall out of one piece of foamcore and just winged it. It came out 5 feet by 6 feet and 2 inches. Now I can smoosh fabric around too!