My basic design is a triple tiered skirt, with the tiers stitched to an underlying full length skirt. I decided on a finished skirt length of 45". Since there are three tiers, that meant that the visible portions of each tier would be 15" in length (red lines and text below). Of course, the tiers actually needed to overlap a bit, so that adds about two inches to the top edge of the second and third tiers (orange lines and text below). There isn't anything overlapping the top edge of the first tier, so it doesn't need those extra two inches.
Oh look! A handy dandy visual aid!
All tiers needed seam allowance added to the top and bottom. I choose to add 1" to the top so I had a nice fat allowance for sewing it to the skirt, and a mere 1/4" to the bottom for a tiny rolled hem.
Skipping forward a bit, I'd like to point out why it's a good idea to sit down and do all the above math ahead of time and WRITE IT DOWN. I didn't. Instead I was doing it in my head as I went along. That resulted in this error-
This is bad. Don't do this.
I forgot to add those extra inches for overlap and seam allowance to the middle tier, which ended up leaving the top edge of the bottom tier exposed. I had to take a big tuck all around the middle of the underskirt to pull the bottom tier up two inches, leaving me with a skirt that is a bit short and barely covers my hoops. Thankfully, I also screwed up and made my third tier too long, so that tuck actually ended up making all the tiers look more or less equal in length again. Happy ending aside, don't be like me. Plan ahead and you'll stand a good chance of not f***ing up all your hard work.
Back to the math! I like to squeeze a fair amount of fabric into my skirts. To get that super full look and make sure that each tier had a proportionate amount of fabric, I measured the circumference of the skirt at the point where bottom edge of each tier would hit and tripled that measurement. For example- the hem of the skirt was 10 feet around, so I tripled that and gathered 30 feet of fabric for the bottom tier. Repeating that formula for the other two gave me 25 feet in the middle tier and 20 1/2 feet in the topmost tier.
The Actual Sewing
I ripped my fabric into the appropriate heights/widths for each tier (yay for ripping fabric!) and got to work on hemming. 75+ feet of fabric is a lot to hem, so to save my sanity I used my secret weapon- a narrow rolled hem foot. You feed your fabric into this lovely thing and it turns the edge over twice to encase the raw edge, then stitches it all down. It makes for a perfectly finished tiny little hem.
Mah super sekrit weapon
I set aside the tiers for a while to work on the underskirt. I draped a six panel gored skirt that fitted closely over my hoops and sewed it up in a basic white cotton fabric. (Edited to add: I forgot to mention I should have made it out of the same polka dot fabric so that the underskirt wouldn't stand out if one of the tiers flipped or flew up when dancing) I measured down 15" from the waistline to mark where the bottom edge of the first tier would fall, then another 15" down to mark the bottom edge of the middle tier. I drew lines 2" above each the first two lines to mark where the tiers would actually be sewn on.
I have nothing interesting to say about this photo
I gathered each tier to fit the skirt, then sewed them on upside down so that they'd have a little extra ompf when flipped down to show the right side.
Tier flipped down to cover seam allowance
Sewing the first tier on wasn't so bad, but by the second and third ones the massive amount of fabric involved threatened to engulf my machine!
My machine soldiers on, oblivious to the fact that it's about to be eaten by the very fabric it's trying to sew
But bit by bit it all came together...
As mentioned earlier, I sewed a tuck all around the middle of the underskirt to correct for the too-short middle tier. Last but not least I added a waistband (still have to sew on large hooks and eyes though).
And finally, a finished triple tiered skirt!
Now for that bodice...