How To,  Pattern Reviews,  Sewing Tips

How to True a Bikini Panty

Designers sometimes offer free, or almost-free, pdf patterns to let new customers try their product. Yesterday I spent $.99 to try a Little Finch pattern. I chose the Quicker Knickers. This is a cute basic bikini/brief, but unfortunately the grading is inconsistent: these are the side-seams, with a variety of shapes and lengths that aren’t nested (the largest size 3X side-seam is SHORTER than the smallest size 2):


More importantly the pattern is not trued. But that can be fixed. Here’s how to true the Quicker Knickers pattern in 3 easy steps. (Note: the pattern  includes fabric bands at the waist and leg openings, yet the basic design of the panty itself should have a smooth fit, so I’m only showing the pattern NOT including the waist and leg bands,  for visual simplicity.  Also only small parts of the pattern are shown, just enough to indicate the corrections).

  1. Side-seam bubbling: the side-seam has  a very rounded curve, creating a bubble when stitched:


The side-seam of a panty, just like pants or shorts, should be drafted with a hip-curve that is more shallow than a French curve, to eliminate that bubbling. Photo on left shows a hip curve on top, a French curve on bottom, and a combo in the middle. The combo has a French curve on the upper end and hip curve on the lower end. I grab a combo for everyday quick-and-easy corrections:


2. Waistline:   The top corners of the side-seams are not trued; they have (depending on size) moderate to extremely acute angles, so that when the side-seam is stitched,  the result is a deep “V” shape  along the waistline edge…..sure, this “could” be a design -feature, but looking at the photos on the pattern cover, it seems like the designer was going for a straight-across waist:


It’s helpful to see the pattern pieces  on the dress-form to understand the correction, because it’s a bit counter-intuitive. There’s a saying in pattern-drafting that “A straight line on the body is a curved line on the pattern, and a curved line on the body is a straight line on the pattern”.  Here’s what that means: the waistline on this pattern is straight across:


It will not be straight across once on the body, it will curve downward at the side-seams:


So, to make it “look” like the waistline is going straight around the body, you have to curve the pattern. Brilliantly, this also automatically trues the corner, cancelling that “V” on the side-seam and making a smooth waistline!



(Edited to add:  The back gets a shallow scoop, the front gets a deeper scoop, depending on your fitting preference):


Generally the waist  of bikinis scoops lower in center-front than in center-back:



Try it: cut out a muslin swatch with the revised curved-waistline pattern: on the dressform the  waist “looks” like it’s going straight across:


See what I mean by counter-intuitive?

Original with STRAIGHT waist pattern….Revised with CURVED waist pattern



The last fix is really simple:

3. Crotch Shape: the front-to-back crotch isn’t trued, there’s no smooth connection from the front to the back.  Even adding the fabric leg bands, the angled cut-out  creates a disconnect from front-to-back. The front crotch gets narrower and narrower as if it’s going to be a thong, and then boom! Suddenly there’s a full brief in back:


This is an easy fix: simply French-curve the front to the back:


And that’s it!

In the restaurant business, there’s a saying that “You’re only as good as the last meal you served.” .  Because that’s the one your customer remembers. The same thing could be said of the pattern industry. It’s sad, but even one experience with a pattern that needs work can make you avoid that company going forward.  If  you’ve had better experiences with Little Finch please let me know. I’m always willing to try again.

Edited to add: this is off=topic (not about trueing) however I received a question about how to adjust this pattern for a higher back rise and shorter front rise.  You can “slash-and’spread” the back (left), and take a fold in the front (right):




  • Dianna

    Absolutely wonderful post! Thank you for sharing! It’s horrible when we constantly have to rework a pattern. If I have to drafting anyway, why buy the pattern?

  • Auschick

    So helpful thank-you! I’m now realizing that I have a hip curve and not a French curve. Time to get a new tool!

  • [email protected]

    That’s exactly what my husband always tells me! “Why are you buying that if you know you’ll have to fix it?” For me it’s because I’m not a fashion designer, I’m a technical designer, so I want to see what the fashion designers have designed (if that makes sense). And lucky for me, I can correct drafting issues. But I do feel badly for the sewist who has not been to pattern school….which is probably 99.9%.

  • Shelley

    Thanks for sharing your wisdom. It’s a great service to let others know how to tell what’s in store with a pattern before they find out the hard way or worse, think they made the mistake. Icing on the cake is explaining how to fix it.

  • Cyn

    Thank you so much! The pictures really help explain it so much better. PS. That fabric is adorable.

  • Leah Cain

    love your blog!! i bought this pattern too (couldn’t resist the price!) and now i know what to expect

  • JustGail

    Another reason you buy these patterns – so you can enlighten us about the problems some of these new pattern companies are putting out, and that ever more frequently, it’s not us, it’s the pattern at fault when a project turns to crap. Please tell your DH that we are very happy with your reports!

    The downside of your posts is – I’ve often thought of drafting my own patterns (I have no training other than reading books and internet), but now realize how much needs to be checked. But then, I’d only be drafting to my size. I also notice on this pattern it looks like there’s some uneven-ness in grading between sizes?

  • [email protected]

    Well usually I do buy patterns with the intention of using them, to add items to my little Etsy shop…..that is how I discovered “pdf world” to begin with….but this time I chose a pattern purely to check out the designer. Certain designs are a better test than others to see what the patternmakers skill level is. There are entry-level garments (twirl skirt, peasant dress) that require little knowledge of drafting or fitting, and then there are more specialized items (pants, underwear) that can take many years to learn. The specialized items are a better way to see if the designer is putting out a technically well-designed product. But whatever the garment, it breaks my heart to hear about the consumer blaming herself for a bad outcome, or simply procedural frustration, that is not due to sewing but rather to drafting.

    You CAN learn to draft your own patterns…the internet is an amazing source…and every project you do is a learning experience. Although I’m completely unfamiliar with them, I’ve heard that there are great online classes you can take.

    Yes you are right, the grading on this pattern is uneven….the side-seam lengths are not proportionate, they seem somewhat random. This is usually a sign that the pattern was drafted in Illustrator or similar non-pattern-specific vector program. Had it been drafted manually and then uploaded, the sizes would automatically be “nested” by using either the slash-and-spread method or the shift-up-and-over method. If it were drafted in a ($$$) professional digital program like Accumark, the program itself would notify the user that the side-seam lengths were off. Generally in bikini/brief patterns there is an increase in side-seam widths in proportion to the increasing garment sizes. Not always: a string bikini has the same tiny side-seam in all sizes, and Hanky Panky thongs use the same width of stretch elastic for all sizes. But a pattern with side-seam lengths that jump up and down? I can’t find a reason for it.

  • Rosie

    great post. For me, a few bad “last meals” have turned me off of PDF patterns entirely. But I grew up on Big 4 so they don’t intimate me in the least. They are not without their problems, but are at least usually drafted well and don’t have fan girl gushing”review” issues. 🙂 I’d rather deal with properly fitting a reasonably well-drafted pattern with outdated fit models that give too much ease than fix bad drafting any day.

  • [email protected]

    Same, I grew up on Big 4…totally agree that they’re not perfect ( they’re “reasonably well drafted” lol) however you generally learn which one fits your body type, and the instructions are fairly predictable. In pdf world, the quality varies enormously….I’m trying hard not to be turned off, to keep trying, and find out if there are little fixes that can turn a problem pattern into one that’s usable. Thanks for reading!!

  • Cecelia

    This is a great post. I hope the designer sees this and works on improving their patterns. It’s refreshing to have honest reviews and especially how to fix things!!!! so many reviews are all rainbows and puppydogs.

  • [email protected]

    But I love rainbows and puppydogs!! Truth is there are a lot of patterns out there that need a few tweaks….sometimes just a couple of little adjustments make a world of difference! Thanks for reading.

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