Shady Lanes - Bordering Math

I almost made a critical mistake.  I almost cut my red fabric for the borders.  Then I remembered that the sawtooth border will be added after the red, so I can't just proceed as I would normally.  I have to finish making the sawtooth strips, then get the final measurements before I cut the red... so I know how wide to cut the red strips to make up the difference between Border # 1 and Border # 3.  Otherwise I may end up having to chop off part of a sawtooth to make it all fit.

I knew I read somewhere how to do this and had to rack my brains to remember where. Coffee helped.  Chocolate helped even more.  Quiltville, of course.  I clicked over to Bonnie's site and read through her article Border Hints.  Lots of great advice on adding borders but not the process I vaguely remember reading for measuring and adding a pieced border.  And I was so sure it was something I read on Bonnie's site... willing to bet some of my Hallowe'en chocolate on it.  Actually, I've eaten so much of it today, I'm feeling a little sick.  Then it came to me, it was part of the instructions on bordering the Orange Crush Mystery.  I am frequently amazed at the accuracy of my memory when it comes to quilting, when I can't remember if I paid the utility bills this month.

I have made pieced borders before but not one in which the pieced component couldn't be fudged, and by that I mean trimming off a little here or there to make it all fit.  I would so hate having to slice half-square triangles in half and losing the points.  I'll be joining 2.5" half square triangles into sawtooth strips this evening to finish making my border # 3 strips, so that I know how wide to slice the strips for border # 2. 

I'm glad I remembered before I sliced up the red fabric.  Some days are better than others.