Raglan Sleeve Low Back One Piece

Let's Mix Things Up A Little

Previously when I made swimwear with sleeves it was all based on a 12% block and I'd planned to make a 12% sleeve block. I didn't do much dance or cosplay work, and certainly not any reversibles, so I never really had much need for an 8% block.

However one of the limitations of the 12% blocks was they tended to be a fraction too tight once sleeves were added. Sleeves can pull a little when they're very close fit and this tended to make swimwear slip between liner and fabric once wet ... the liner would stick to the body, but the fabric would move ... not a good look but that's what people did back then. I have started noticing that many brands are now dropping the liner altogether when they add sleeves .... and compensating by using a thicker fabric. Obviously you don't line the sleeves anyway. One piece swimwear is already difficult to take off when wet and with sleeves it's even more sticky.

The other thing I've noticed is that some are droppping the ease down quite a bit (5-8%) as well as losing the liner. This makes sense from a structural point of view, however I'd still like to see at least the crotch lined, even with a thicker fabric .... old habits die hard.

So as I already have both sleeves and body blocks made in 8%, I think it's time I changed to doing swimwear with sleeves and start using the 8% negative ease blocks when making swimwear with sleeves. This will not work so well with reversibles as the tension and slippage would be too much together.

There's also another reason I'd like to use the 8% block more. Styles like the one we're going to demonstrate today tend to gape when you cut below the waist line ... reducing the ease would go a fair way to reducing that gape without having to change too much more. But don't be thinking that changing to 8% for everything would be a good idea as it will reduce the ability of the fabric to contour properly on tight curves .... you need that tension (along with darting) to create shape. You need to select the correct tension for each task ... much like sewing.

So the style we're looking at in this tutorial is a mid length raglan sleeve on an open low back one piece. I'm using the women's 8% sleeve block to match the women's 8% body block for a 92cm B/C bust to demonstrate (you'd choose the size that suits you). The first two photos represent the front and back.

But wait, there's more, I'm also going to add the flouncy sleeve cuff we see in the third photo to demonstrate how that's done ... you can ignore it if you don't want it in your swimsuit. And I'm going to cut away the shoulder section as in the fourth photo too .... again, if you don't want it then just ignore that step. I just want to put as much into the tutorial as possible. And lastly I'm going to sexy up the whole thing by using the high cut semi-thong back you see in the last photo. We're going to really mix this up! If you do happen to make it exactly as it is here then I want photos!

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 these designs as an example to teach students how to manipulate a block into a pattern that resembles this style (albeit, probably not exactly).


Step One

There are several different Raglan sleeve methods for wovens (non-stretch) and they're constantly being applied to stretch patterns. Typically they involve first sketching the raglan seam design lines on the front and back blocks, then cutting them off the top of the blocks and sticking them onto the sleeve head (Here's a link to an example). You might have noticed that this still leaves you with seam line right down the middle of the sleeve ... something we really don't want in stretch patterns. Some people then distort the patterns to straighten them up so they can be put together and made into a single piece .... this is what I call taking a bad start and making it worse because it results in huge gathers and ripples under the arm (see the design in the first photo)  ... but it's extremely common and does result in a straight Raglan line.

There is however a better way, as odd as the method might seem, but it doesn't so much allow for a straight Raglan line as you approach the armpit ... I still think a curved line suits the body shape better and it certainly results in a far better fit. So I'm going to show you how and why!

Put the top half of each body block together at the shoulder seam and then put the sleeve block parallel to the shoulder seam, matching the notch on the sleeve block with the shoulder seam as illustrated. Draw a guide line (red) between the notches on the back block and label them A and B. Do the same on the front block and label them C and D. You can click on the illustration to open it up larger in a pop up. Draw a guide line (green) from point B to intersect the back neck at exactly a right angle, label the intersection point E. Draw a guide line (green) from point D to intersect the front neck at exactly a right angle, label the intersection point F. Note that the back is closer to the shoulder seam than the front.

Now draw a guide line (blue) from point E on the back block to make a tangent with the lower arm hole, label the intersection point G .... mark point I halfway between A and G. Draw a guide line(blue) from point F on the front block to make a tangent with the lower arm hole, label the intersection point H .... mark point J halfway between C and H.

Raglan One Piece-01.jpg

Step Two

Draw in the back sleeve line (red) starting at point E, closely following the guide line and curving in smoothly to the sleeve at the end. Do the same on the front block (blue). Now draw in the raglan line on the back body block starting at point E (orange) and gradually curving into point I. Repeat for the front block. Make sure you're square at the neckline everywhere, and smooth into the armhole or sleeve at he other end of each line. See illustration.

Raglan One Piece-02.jpg

Step Three

To show you why this works better we need to consider two things. Firstly, we do not have a seam right down the middle of the sleeve which means our grain (for want of a better word) is straight, our prints won't have misalignment issues and there's no extra sewing to go wrong. Secondly we haven't had to distort anything to create the straight raglan sleeve ... take a look at the illustration below ... the extra pattern space we have at the back of the sleeve head is very similar to that removed from the back block .... and the same goes for the front. So we've lost/gained less pattern area than the distortion method AND we did it without distorting anything.

Raglan One Piece-03.jpg

Step Four

Next check that your seam lengths match. If you need to lengthen or shorten anything, do so on the body block, not the sleeve, by pushing the curve in or out slightly in the middle.

Next, square down from the top of the old sleeve head 55% of the way to the wrist ... square across (red) ... this approximately represents the elbow. The cut out in the sleeve head starts about half way between the elbow and original sleeve head (blue) and continues to about halfway to the neck (green). Square across at both these distances. Draw a guide line (pink) from the bottom of the cut out at the blue line to half way along the green line .... this represents the center of the cut out.

Raglan One Piece-04.jpg

Step Five

Without being able to closely examine the top of the cut out design in the photo I'm going to guess that it's a simple oval shape. It may well be angled to a point with a seam near the neck to make elasticating easier, but it's not possible to tell. So draft in a narrow oval shape, centered along the pink guide line. You don't need to make this a very wide oval as it will tend to open up much more on the body. See the illustration for the proportion I've chosen. 

Step Six

Now for the fun part of making it all happen. Put the sleeve up to the back block at the neck. When creating a clip at the base of the neck we need to drop it about an inch from the nape. I've drawn in a little 25mm wide by 30mm high rectangle, 25mm down from the nape, representing the clip I'm using (the slots on the clip). Curve the back neckline into the top of the clip. Starting at the bottom of the clip, draft in your desired back cut out shape. I've chosen to use an angled V style at the bottom to better match the half thong leg line I'll be doing. To avoid gaping I'm also staying away from the side seam, getting no closer than a third of the width of the block. You can go closer if you'd like but be aware you may need to reduce horizontal negative ease a little in the front block between the bust and waist to reduce the inevitable gaping.

Put the bottom of the front block along the side seam of the back block. I've chosen to match the leg height of the last design photo and sweep rapidly down to fall into the cheeks half way down (ie; halfway between the waist and crotch seam being just under half the width of the bottom block). The design in the photo is not a thong, it's a gradual curve that gathers between the cheeks, halfway up. Continue a similar style on the front making it a little narrower at the crotch.

Step Seven

Put the bottom of the front block to the back block, overlapping the front crotch seam to around halfway to the hip line on the back. We need to reduce the body length because of the narrower width. How much really depends on how narrow the back panel is and how much rebound is in your fabric. It's not something I can specify exactly without knowing your fabric ... this amount would be about correct for a back panel that's been reduced in half for an average 180gsm lycra. If your fabric is lighter then overlap some more, and vice versa.

Join your front and back leg hole designs smoothly. Select where you'd like to place your crotch seam .... it's arbitrary but don't go too far forward. I've placed mine halfway along the overlap (green).

Smooth off the back side seam (blue).

Raglan One Piece-07.jpg

Step Eight

Put the bottom of the front block back with the top and smooth off the side seam (red). Remove unnecessary guide lines. Bring the front dart back about 1.5cm from the bust point (green) .... I think that a nice straight princess line would add something to this style but we're already overloaded with features so maybe next time.

Raglan One Piece-08.jpg

Step Nine

Add seam allowances and fold over elastic allowance .... I've used 10mm everywhere ... you might reduce the shoulder cut out to 5mm if you want a softer line. Make sure to label everything with Style name, panel name, how many to cut out, sizing, date and revision number, and author name.

Now lastly we're going to add the flounce to the bottom of the sleeve cuff. From seam to seam mine measures exactly 230mm, but its at 8% negative ease around the arm .... on the body that would really measure 250mm. We need to be aware of this because we don't wish to lose any of our "flounciness".

Raglan One Piece-09.jpg

Step Ten

In the center of the top image is my 230mm circumference circle (black), around that in red is the 250mm circumference circle. We need a ratio of at least 3 to 1 to get all that volume in the flounce ... this means we need at least 750mm in the outer circle, or we would need more than one circle to get the fullness. The length of the cuff in the photo is around 100mm, so if we increase the radius a further 100mm we get a circumference of 878mm or a ratio of  1:3.5 ... which is about perfect for a big fluffy flounce like this one.

I've added a 10mm seam allowance to the center only to match the sleeve because I will stretch the sleeve and flounce slightly while sewing and allow the over locker to trim the excess as I go. If you're not comfortable doing this you could reduce both the sleeve cuff and flounce to as little as the width of your overlocker but it wont give as neat a finish. You don't need any seam allowance on the edge of the flounce ... let it flow softly. Don't forget to label your flounce.

Raglan One Piece-10.jpg

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