Mitered Corners / Mitered Binding Corners

Patterns often tell you to stop a ¼” from the edge of the fabric.

What they really mean is stop right at the seam line, which is a scant ¼”. That’s the secret to sharp mitered binding corners and precise set in seams and the Prep-Tool can help.


The secret to sharp mitered corners, including mitered binding corners is to stop right at the seam line.

The Prep-Tool is a Scant ¼” wide and its raised Lip Edges catch the edge of your fabric, so you’ll always mark the exact stopping point every time.


1) Butt the Lip Edges on the Prep-Tool against the edge of the fabric and mark your stopping point.

2) Sew up to the stopping point and then at a 45º angle into the corner.

3) Fold the end of the binding straight up to form a 45º angle.

4) Keeping the 45º angle underneath, fold the binding back down, and start stitching a scant 1/4" from the edge.

Sew Accurately
Measure / Mark Seam Lines & Pre-Trim Points:

Prep-Tool with 8-page
booklet & 1 Seam Guide

Sold out

Square up the super easy way,
cut & sew accurately:


Perfect4Pattern Sets
include the Prep-Tool
and Guidelines Ruler(s).

Square up the super easy way,
cut & sew accurately:


Perfect4Pattern Set
for regular acrylic rulers
you already have.

Square up the super easy way,
cut & sew accurately.
Plus: Make Blocks Any Size
No Math!


Finished-Size Quilting Sets

The Prep-Tool comes with one peel-and-stick, self-adhesive Seam Guide with removable, reusable adhesive. They are 1/32" thick making it easy to align and guide your fabric accuratly before it gets under your needle.

The Prep-Tool also includes an eight page instruction booklet that you can download to view or print.

Replacement 6-Packs of Seam Guides are available separately. Click here to get a pack.

Sew accurate
scant 1/4" seam allowances:

Learn More .

Pre-trim triangles & diamonds

Learn More.

Take the guesswork out of
Set-in Seams

Learn More.