How to Correct a Mirrored Knit Shorts Pattern

Here’s a quick review of a new free pattern that was released today, the Tupelo knit shorts from SewLikeMyMom.  Like several other pdf kids’ knit pant/legging patterns, it has a mirrored front/back rise, with instructions to adjust the rise height by trimming off the waist at an angle (photo shown under Fair Use doctrine for the purpose of product review):

I will show you  how to adjust this pattern (and others like it) for a better fit.  Because this is in stretch knit, you can get away with sewing this pattern “as is”, however it will cause great fabric strain at the center-back seam, due to the lack of length and coverage of the back rise.

• Woven patterns that rely on excess fabric will provide coverage but not good fit.
• Knit  patterns that rely on excess stretch will provide coverage but not good fit.

The pattern prints out on 2 sheets for the shorts body, and 1 sheet for the self-fabric waistband.  I will concentrate on the body only; the waistband adds height to the rise but I’m not discussing height measurements, only proportion and angle.

Print the pattern  twice and tape together at the fold (photo looks a bit wonky as the camera angle is off; this is a mirrored pattern):

Before working on the rise problem, let’s take care of a few details. The pattern needs to be trued at the hem….before trimming the side-seam off, fold up at the leg hem:

Then trim off the side:

Unfold back down:

Draw in trued hem (repeat for left side of pattern):

---

 

Next true the top of the inseam so that you won’t end up with a point into the crotch when stitching the inseams together front-to-back:

Square off a 90-degree angle:

Draw in all sizes:

…and also repeat for the back.

 

---

Now to the rise issue. The back rise should be about one and a half times the length of the front rise….it can be less if your child has a flat bum but never less than one and quarter times the front rise. The instructions say to trim off the top edge from nothing at the center-back, to 1″ at the center-front:

That won’t give you enough difference in back-to-front rise, but it will result in a “vee” dip at center-front and a “peak” at center-back:

…

This means that when the self-fabric waistband is stitched on, there will be strain on the waist fabric in front, and a bubble in the waist fabric in back. Instead of trueing these corners right now, wait ’til the rises are corrected and I’ll show you how to automatically true this area.

---

 

The bigger problem is there’s no room for the bum. The flat-pattern way to fix this is to “slash-and-spread” the pattern. Splice the back pattern towards the buttocks:

Then spread:

Tape the  pattern onto of a plain sheet of  paper. Connect the drafting with a straight-edge and French curve at the  rises (shown after trimming excess paper):

…

… and a hip-curve to smooth out the waistline (again shown after trimming….I took these photos as an afterthought, sorry):

..

and hemline:

 

And voila! This is the shape of a better-fitting knit shorts, with all corners trued for ease of construction:

---

 

Post-script: if you plan on using this pattern please note the grade needs correcting. (The following calculations were done BEFORE adjusting the pattern for shape: this is just to give you an idea of how you can tell adjustments are needed on the original pattern.)

I calculated the waist of the shorts body (pattern front-plus-back, not including seam allowances, doubled for left/right):

…and the waistband (pattern front-plus-back, not including seam allowances, doubled for left/right):

…and the measurements don’t match up to the chart given:

The shorts body grade is between 1/4″ and 3/8″ , and the waistband grade is 3/4″ . This means the shorts body is getting proportionately bigger in relation to the waistband as the sizes decrease.

Size 8 :  you stretch the 19 1/2″ waistband to the 22 3/4″ body to get 21″. That works.

Size 12m: you stretch a 13 1/2″ waistband to a 20″ body to get 15 1/2″? That doesn’t work.

The shorts body  grade is too small.  It’s just slightly over 1/16th of an inch per quarter (front/back/left/right). I would start by doubling the shorts waist grade.

As always, be sure to make a muslin when using any new-to-you pattern!