First I find out the length of the final piece of tulle - so basically, it's the hip measurement of the tutu. This seems to be a little bit complicated because the top layer ends up having a slightly smaller circumference than the bottom layer because of curves. However, as you don't want to stretch the lycra as you sew, I just make it for the top layer and it works out through the sewing anyway the way I do it.
So, measure across the leotard, then double it.
I get some fishing line. I've been using 6lb, 0.25mm line, it's thick and visible but not too thick that it doesn't bend well. When I sewed cotton fabric, I was using yarn mainly because that was within arm's reach at the time, but yarn would get caught on the edges of the tulle and cause bad words, so I decided on fishing line.
I tie a loop in the end of the fishing line, and triple knot it so that the knot is quite big. Then I measure the length I want my tulle to be and do single knotted loop at the end of that, re-measure to make sure it's in the right spot, then add another two knots. Then snip the length off the fishing line.
I make all the lengths at once - I need 6 for this tutu - and stick them in a drawer next to my machine. I put them in the drawer only because otherwise my cat thinks they are for playing with.
You can see the loops in the picture below..... maybe.
To gather, I use the cording foot on my sewing machine. I put the first loop out on the back side of the work, then snap the fishing line in to the middle cording groove. I set the machine to a wide, long zigzag stitch (5.0w x 5.0l).
I also use invisible thread for all the gathering, sewing on the tulle and tacking. It's pretty great stuff and I haven't had a problem with its strength as yet. It's so fine you'd think it'd snap, but it holds up to a lot of pulling. I mean, don't try to break it with your hands if you do so with cotton thread, ouch! Using the invisible thread makes all the work for the skirt disappear. It also cuts down on the bulk around the middle. Plus, no colour matching needed - I hate standing at the Gütermann stand with a piece of fabric trying to decide between two (or five) slightly different shades of a colour to colour match......then getting home to realise it shows up quite well on the fabric when sewn.
I also use invisible thread for all the gathering, sewing on the tulle and tacking. It's pretty great stuff and I haven't had a problem with its strength as yet. It's so fine you'd think it'd snap, but it holds up to a lot of pulling. I mean, don't try to break it with your hands if you do so with cotton thread, ouch! Using the invisible thread makes all the work for the skirt disappear. It also cuts down on the bulk around the middle. Plus, no colour matching needed - I hate standing at the Gütermann stand with a piece of fabric trying to decide between two (or five) slightly different shades of a colour to colour match......then getting home to realise it shows up quite well on the fabric when sewn.
As I am sewing, I line the right hand side of the foot up with the edge of the tulle, and the cording foot keeps the fishing line right in the middle. Makes for a nice, even gather.
I hold on to the other loop as I sew, and it bunches the tulle up at the back, gathering as I sew. Be careful not to gather it too much right at the back of the foot, or you can start to sew over the top of your gathers, so stop occasionally and play the tulle out along the line so you know it's sitting well.
Picture below shows the cording foot and the gathered tulle at the back.
As I'm done each section I hang them on a hanger in order. I swear, the amount of times that I have had to remeasure a piece to know what number layer it is is ridiculous. It is actually pretty important to keep your layers numbered and fastened together separately from the cutting to the sewing. Going with the assumption you like your sanity.....
Stay tuned for Phase 3: Sewing the Tulle to the Leotard.......