Yet another essential part of the 18th century woman's wardrobe was the petticoat. You can't go around wearing breeches after all! They can be made from linen, cotton, or silk. They can be made to match a gown or as a separate piece. They attach at the top by splitting in half
(also allowing for openings to reach the pockets) and the front and back have ties which wrap around the waist separately. The most complicated part of a petticoat is its pleating. Up until 1780 I'd recommend 1/2" pleats, which is what I use in the formula below. After that, you can choose to do smaller pleats. The same progression occurred with the gown as I'll talk
about another time.
The first step is do to some measurements. Put on your shoes for this. First, you'll need your waist. Next measure from the center front of your waist line to the floor, then side, then back. There might not be much difference there, I'm only 1" shorter in front. Dipping down the top before pleating means I don't have a curvy hem. Particularly useful when wearing hoops and the difference is great.
When purchasing your fabric, the first thing you need to know is how many panels you will require. Most petticoats use either two or three widths of fabric; 100" to 120" is a good normal range. A finished petticoat should be about 3" off the ground and the hems were often narrow (1/4" turned twice) or faced with tape. If you're going to be working in the petticoat (ex. cooking over the fire) a couple inches shorter is fine.
Once you've purchased and washed the fabric, it's time to cut the panels. Cut across at the fabric the panel length we determined earlier (side to floor minus 1"). If you have three panels, this process will be a bit different, so skip ahead to your own section below. Otherwise we need to curve the top. First, find the difference between the front and side measurements. Mine are 39" and 40", so I have a 1" difference. Find the middle point at the top of one panel. Mark down that difference and mark half-way between the center point and the side at top. You'll create a curve as shown below.
For two panels, you'll stitch up the side seams stopping 9" from the top. By hand, I use a combination of running and occasional back stitches. The top 9" you'll fold the seam allowance back, then fold the edge under to hide it (like a roll hem). Use small whip stitches to tack it down. I also recommend putting a thread bar at the bottom of opening to keep the stress of the seam.
For three panels, stitch all the way up all three seams. By hand, I use a combination of running and back stitches. One seam will sit at center back and the other two will end up on your side fronts. Find your center front point at the middle of the front panel. Match the center back and center front points. Lay it out flat and the folds should lie where your side openings will be. Mark and cut a 9" line straight down from the top and these points. Roll and hand-stitch the raw edges back. Around the bottom do a hand button-hole stitch and a thread bar.
Next comes the pleating. Find your waist measurement and also measure the front or back half of your petticoat. Before you start, is this to go with a gown or is it separate? If you're going to use a gown, you'll have a 5" pleat at center front. Otherwise, I recommend a 3" pleat. You'll see two different formulas, the first one for the 5" and second one for the 3".
"Waist" is your total measurement
"Fabric" is just the front or back half of your petticoat
Round to the nearest 1/8" for "per pleat"
Waist = _____ / 4 = _____ - 2.5 = _____ x 2 = _____ pleats (gown)
Waist = _____ / 4 = _____ - 1.5 = _____ x 2 = _____ pleats
Fabric = _____ / 2 = _____ - 2.5 = _____ / pleats = _____ per pleat
Fabric = _____ / 2 = _____ - 1.5 = _____ / pleats = _____ per pleat
Place pin center front (CF). Place a pin on either side either 2.5” or 1.25” out from CF.
Next pin goes ______ (per pleat) further out. Place one 1/2” in from last pin.
Repeat until correct number of pleats has been marked. The last 1/2” should be at the very end.
If the last pleat doesn’t end in the correct place, determine the amount off. It should be less than amount per pleat, but more than 1/8”.
Subtract or add 1/8” to pleats working from the end in until it evens out. (If you’re 1/2” over, the last four pleats need to be 1/8” less than originally planned.)
Fold pin to pin with pleats facing out, leaving larger CF pleat as measured.
Waist = _____ / 2 = _____ pleats
Fabric = _____ / 2 = _____ / pleats = _____ per pleat
Place pin CB.
Next pin goes _____ (per pleat) further out. Place one 1/2” in from last pin.
Repeat until correct number of pleats has been marked.
Adjust the last pleat distance to 1 1/2” including the 1/2” marking.
Move sets according to front directions to correct.
Fold pin to pin with pleats facing inward.
Do a running stitch 1/4" from the top to fasten the pleats down.
Cut two strips of 1" tape (cotton twill or linen) half of your waist size plus two tails of 30" each. Fold it in half over the raw edge on top and stitch down. Make sure to roll and stitch the ends of the tape.
To hem, try it on and make sure it's even with the floor. If not, have a friend go around and mark 3" above the ground with pins. Leave 1/2" past your finished length. Roll and stitch with a slip stitch so you won't catch it on your heels.