Maybe the author is a designer/sewer and not a quilter as such.

I would cut the pieces for 1 block and use her seam allowance and see if it comes out the size it's supposed to, if not then I would adjust the seam allowance, since it is strange to have 1/2" seams for quilts. It also could be a misprint or a mistake.

Okay, I know I'm showing my age with this post but here goes. When I was a teen, someone gave me some quilt templates. I was instructed to trace the template onto the fabric and then cut an ample seam allowance. There wasn't an exact amount like we use today. I tried doing as I was instructed but didn't like it and didn't make any quilts. I was a sewer...... 5/8" seams for clothing. So, when I started to try quilting again, I thought 1/4" was insane. Wouldn't the seam pull out??? Silly me.... the quilt is stitched together with batting and backing. No way could the seam pull out unless you mistakenly didn't catch in the edge.

Quilting has come a long way..... a really long way. I actually started quilting back around 1995 although I did do a baby quilt for my youngest son in 1976 ..... the old method. I now have tons of gizmos to do quilting.... my DH says that if they make it for quilting, I have it..... not true!!

Why would someone write a book using 1/2" seams?? Who knows. I'd just follow the patterns in that book with 1/2" and do the normal thing, 1/4", for other quilts. Problem solved!!

Thank you ladies, I did go and read the reviews on Amazon and this book is not a true quilters book, it's pretty but has no real instructions or true techniques as such. I will make some things from it using the 1/2" as required but I have found a great blog showing me how to make a 'proper' quilt with amazing instructions.