You could make strip sets and cut the triangles from those. Start with the right angle at the top. Then the next cut will be the right angle on the bottom, ..... You'll end up with two sets of triangles that will produce two different blocks if pieced the way shown in the photo.

Since the picture you linked to is from a blog that is still active today, why don't you just send her an email and ask?
[email protected]

If I were you I would paper piece (or other foundation). You can even draw the lines yourself on paper and make as many copies as you need - that way you'll have wide and narrow stripes just as you like it.

ahha ... looking through her blog closer, at the end I found this sentence

"After making all these blocks my sewing room was an absolute disaster! There were stacks of fabric, piles of scraps and bit of torn foundation paper everywhere! "

so yup ... she paper pieced them.

I'm with Charsuewilson - make strip sets and then cut - This quilter uses some nice funky colors.

Thank you all for your help and ideas. After reading all your replies, I'm excited to start this quilt. Of course I have to finish the one I'm making right now first! :) My daughter's room is white and pale mint green. She has my grandmother's old cast iron bed that I refinished in white with gold accents. I'm thinking about using this collection of fabrics (http://www.fatquartershop.com/Sweeti...1&Store_id=499) with white print fabric. I'm thinking I'll do a checker board pattern with white squares between the multi-colored squares and I'll quilt fancy hearts in the white squares. It is so fun having a girl and being able to do fancy quilts! Thank you again for all your help - this board is wonderful!

I love your ideas for her quilt! Sounds perfect!

Look at the block in a different way. Undo the 4 triangles keep in same places.
Now rearrange them placing the 4 corners as the centre. You have a new square.
I think you cold make this new block in stripes . I would use sew and flip method then cut diagonally to make original block.

https://www.google.com/search?hl=en&...nyAGCvoG4DQYes it is a string pieced block. I do it often. You have bias edges just use starch or a very light weight iron on stabilizer and change-O-presto you've got your block. Have fun they are addicting.

As you are making squares, you could start w/a center square and work out from there, like a log cabin. That way there would be no bias edges. And you wouldn't have to paper piece. I have paper pieced string blocks using telephone book pages (8") and Golden Threads quilting paper (12"). Just another option.

I'm with peckish on liking the ability to get matching to work well with bias edges. Part of that probably comes from my years of sewing clothing and that being a standard technique for getting things to fit well. I will certainly say that when I first started piecing and only used squares and rectangles I sometimes missed having that little bit of "give". And I will also say that my first OBW I should have considered using starch because I chose a fabric that was not very crisp.