Minimal Low Back One Piece

Criss-Cross Low Back One Piece Analysis

This is a somewhat challenging one piece because it's not as stable as it might look. The right hand photo (thanks Keith for finding it) isn't actually the same garment but its close enough for a front anyway. They differ in that the bikini bottom curves up into the body on the left photo, but it's angular on the right ... or at least it looks that way ... not important as I'll make it curve anyway! The front is a reasonably square neckline.

NOTE: Part of what we all did at Fashion School was look at other people’s high fashion garments and see if we could work out how they were made. This was particularly the case for 3rd year pattern making. The teacher would show us a photo of something from fashion week and give us an hour to make a pattern for it … I loved those challenges. At the end of the hour, the teacher would demonstrate how she thought it should be done and why. Some people out there call this copying or “knocking off” someone else’s design … that’s not what we’re doing here … this is about learning how to make patterns by following a procedure … it’s what we all did and how we learned. I’m not telling you to take these instructions and go manufacture this garment for sale …that is wrong and illegal ... I’m using this design as an example to teach students how to manipulate a block into a pattern that resembles this style (albeit, probably not exactly).

This time instead of demonstrating on the Size 10B/C Women’s One Piece Block we drafted previously, I’m going to base this pattern on the RTW Women’s One Piece 12% Block Set for a Bust size of 88cm, Waist of 68cm and Hips of 93cm. I want to do this to show that the block we start with isn’t important for this type of lesson. Before you start each step, take a good look at the illustration to help you follow the drafting process. At the end of each step your draft should match the illustration.

Step One

To start with we'll need the full width of the top of back block to gauge how far our straps will go and at what angle. We'll only need half the lower back block and half the front block. Close out the bust dart by rotating it from the center front bust line.

Step Two

This is the fun part .... cut the back block in half and place each half against the side seam of the front block so we can design straight onto the blocks as a whole. Looking at the left hand photo above, the back strap joins to the side seam about halfway between the bust line and the waist line ... somewhere near the Empire line. I've drawn a red dotted line 8cm below the bust line all the way across the front block. I've drawn in the leg line (blue) a few centimetres higher than my block and a little narrower at the back, with the apex still forward of the side seam in an attempt to get some stability in the back. We'll do a center back seam after to help lock it in place.

The back strap is about 4cm wide only at the top but it appears to widen towards the side seam a little ... I'm going to make it a little more so, say 6cm. I've created two long rectangular guides 4cm and 6cm wide, centered on the mid shoulder and rotated until it hits the red guide line. I've shortened it 5cm because it's long and will need to stretch more than normal to stabilize the front. This amount will vary depending on your fabric and would need to be tested each time ... I'm starting at 5cm.

Step Three

I've created a similar 4cm wide guide on the front block along the BP to mid shoulder line and shortened it 2cm further. I've drawn a guide 7cm up from BP along this guide, representing the top of the front pattern piece. If you look at the left hand photo the angle of the back strap is the same as the angle up under the arm hole so I've created a guide (red) that mirrors the strap along the side seam.

The top of the bikini bottom appears to be about a third of the distance up the side seam so I've drawn in a rough guide for this too (blue).

Step Four

Draw in a line from the lower side of the top of the 4cm strap all the way to the bottom of the 6cm strap.

Draw in a line from half way up the center back of the lower block to the third way guide and extend it all the way to the side seam.

Mark in the arm hole side of the front panel in a smooth curve up to the lower guide on the front strap. 

Note the section I've highlighted in blue. I'm going to rotate all of this in the next step.

Step Five

Rotate the bra section from where the front panel meets the back strap until the dart is closed out ... essentially we're shortening the top of the block the same way we would for a smaller bust ... only this time I'm doing it to copy their reveal of the side of the bust, hence no darting is really required. Curve in the neck line.

Draw in a gentle curve from the back strap to the top of the bikini bottom making sure your curve matches the angle of the guide lines. Draw in the top line of the strap from 4cm guide at the top to the 6cm at the side seam.

Step Six

Draw in the front strap between the two guide lines (red). Remove the unnecessary lines from the back panel and transfer a copy of the bikini back to the bottom of the front panel (blue) .... modify the width of the front lower edge to match the back (red).

Step Seven

Remove all the unnecessary guides and separate the front strap from the front bodice.

Divide the bikini back into three sections below the hip line.

I've also marked in a line on the strap (red) where I'd like to cut the panel so I can make the strap a separate pattern piece.

Step Eight

Rotate the strap to the vertical (on grain) and join the front strap to the back strap ... it might as well be one pattern piece now!

Rotate each of the three sections at the bottom back about 10 degrees each clockwise at the corresponding point on the leg line to create a curved center back seam as shown. Re-curve the bottom back section smoothly.

Step Nine

Remove all guide lines. Add seam allowance (I've added 10mm everywhere for this style). Label each pattern piece with a style name, panel name, how many to cut, size or measurements, date/version and author.

Follow me on ....

  • Instagram
  • Facebook Page
  • Facebook Group

If you find my website helpful, please consider sharing it with others,
or linking to it from your own page.

The real value of knowledge is in sharing it on!

© 2020 by Pattern School Online