Sew Accurate Scant 1/4" Seam Allowances

What is the secret to getting sharp points in blocks like these?

Sew consistently Accurate
Scant 1/4" Seam Allowances.

Use the Prep-Tool to align a Seam Guide on your sewing machine to sew perfect Scant 1/4" Seam Allowances.

Sew Accurately:

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

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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

  • Consistency - To have your blocks come out perfectly square and lay flat, you need to sew all the pieces together with the same width of seam allowance.
  • Accuracy - To have your blocks come out the right size, the width of your seam allowance should be a Scant ¼”.

If you sew nine 2 ½" squares together with a consistent Scant ¼” Seam Allowance, your block will measure 6 ½". That's a finished size of 6" with an extra ¼" all around so it can be sewn to other blocks or sashing to make a finished quilt.

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A Scant ¼” is just slightly less than a full ¼” & the reason
it matters in quilt piecing is actually pretty simple.

The thread and fold in a seam have some width. To compensate for that, you sew slightly less than a full ¼”, so your finished seams actually come out measuring a full ¼”.

That way, all the pieces and the finished blocks come
out measuring the exact sizes the pattern gives.

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.

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The goal is to stick the Seam Guide in front of the presser foot of your sewing machine to help guide your fabric before it goes under the needle.

The Prep-Tool makes it easy to align the Seam Guide so it's a Scant ¼” to the right of the needle.

Guiding your fabric against the edge of the Seam Guide makes it much easier to sew consistently, accurate Scant ¼” seam allowances.

Butt the Prep-Tool up against the needle of your sewing machine on the side with the gold lip edges. Peel the paper off the Seam Guide and butt it up against the other side of the Prep-Tool and stick it down in front of your presser foot.

Remove the Prep-Tool and guide your fabric against the Seam Guide for accurate Scant 1/4" seam allowances.

Butt the gold lip edges of the Prep-Tool up to the edge of the fabric, and you should see the line of stitching right along its edge.

If it's inside the edge, you need to adjust the Seam Guide farther away from the needle.

If it's outside the edge, you need to adjust the Seam Guide closer to the needle.

Click here to see how sewing a scant ¼" helps you
get nice pointy points in blocks like these.

The Prep-Tool takes the guesswork out of marking precise seam lines.

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.

Mark precise mitered binding corners

Learn More.

Take the guesswork out of
Set-in Seams

Learn More.


Accurately pre-trim triangle points:

Learn More.