The Racer Back Tanksuit
When You're After A More Athletic Look
While it may be popular among school, lap and competition swimmers, because it’s a very stable garment that doesn’t move under the rigors of exercise, aesthetically it just doesn't work for me. Furthermore, putting it on and taking it off can be quite a stretch (literally) ... they are, however, comfortable when worn. This style can also be paired with a Princess Line to improve the aesthetic. What I do really love about the Racer Back tank suit is that it does help teach a very important lesson. That a straight cut strap can apparently go around a corner.
There are quite a few variations in this style but they're all essentially a Tee-bar back. Typically the thing that changes are the strap widths relative to the Tee-bar. I've included a slide show of different Race Banks with a corresponding description in the table below so you'll get a better idea of what I'm doing with the pattern. This style really requires a little overall perspective.
Photos found on the Internet (I do not own copyright);
used for the purpose of illustration/education only.
Place the front panel from the tanksuit pattern (without seam allowance) against the back one piece block by lining up the bust line. Draft in a guide the 1.5x the width of the strap that starts on the bust line at centre back and continues upward about 2/3rd the way to Nape (dark green guide). Draft in a second guide the width of the strap starting at mid shoulder and angled down about 60 degrees (blue guide)
Draft in a new armhole curve all the way from the front panel, through to a point on the strap guide 2cm short of the end (as we did for the tanksuit). The curve should be smooth and gradual. Draft in the neck side of the strap making a right angle with the centre back. How easy it that?
Now to add a hole at the centre back. Quite a lot of designers do this in their one piece racer backs, only it’s usually done for horizontal negative eases of less than 8%. If you were to add this type of cut out to a 12% negative ease garment (such as this block), while it would still work, you may end up with quite a few ripples at the sides. This illustration shows the cut out placed as close to the armhole as the strap width (1:1 ratio) that’s as close as you can go. I've also lifted the leg line just 2cm as we decided on doing a high leg design and this helps with the centre back seam.
Remove all the guide lines, the back cut-out and the extra at the leg hole. You could stop here and add your seam allowances, but we also decided on doing a centre back seam at the bottom
Draw in three guide lines horizontally across the back bottom section each about 5-6cm high
Rotate each section about 5 degrees clockwise from the point on the leg line as illustrated below. Re-curve the centre back seam
Remove unnecessary guidelines. If necessary retrace the front and back panels. Add seam allowance to the pattern based on how you intend to assemble it. I've shown this pattern with 10mm allowance for overlocked seams (8mm to blade plus 2mm off cut) and 10mm allowance for folding over 9mm elastic. If you were to use a binder attachment to apply the elastic and casing fabric to the edge, then you wouldn’t need any seam allowance on those particular seams. Finally, be sure to clearly label your pattern pieces with a title, panel name, garment size, cutting instructions, author’s name, date and revision number.
I believe this design would be better with a princess line in the front and back for several reasons. Mainly, this will remove the bust dart from the front and secondly it will separate the top and bottom back sections from each other making it easier to cut (less wastage).