Sloper drape: One dart bodice front

I have started on draping a sloper for use with Marie (my size 12 dress form, if you missed the note about naming her in the previous post).  For the record, I'm using my own class notes from 2006 and the book we used in that same class.  I'm sure it's several editions out of date, but I don't really care; the techniques used are unlikely to have changed significantly.  Where I am going to be fairly detailed in my description, I am not going to repeat the minutia of each step; if you wish to do this, there are many books and online resources to use for the details.  I do, however, want to document my own work and give my gentle readers an idea of what goes into the undertaking.

There is some futzing about that happens before you begin throwing fabric at the body you're making a sloper for.  The form gets a little preparation.  (People do, too, but it's not quite the same; since I'm not draping on a human, I'm not going to get into it since I have no hands-on experience with it.)  I know I already described and posted photos of this, but here it is again, in context.

The form gets a line of tape parallel to the floor at the bust and the hip; at the bust, the drape goes over the stretched tape - called a bust bridge - to make sure the garment fits properly.  This bridge might not be used for things that fit tight (e.g. a bustier or a strapless ballgown), but for a fitting block we definitely want it.  It also gets pins to make it easy to locate key points by feel - the tips of the shoulders, at the level of the screwhole along the armscye, the armhole depth, just below the center neck, the bust points, and if you like the center front along the hipline.  At this point I also took a series of detailed measurements; I was pleased to find that Marie's manufacturer specs were right dead on the money.

Marie looks lovely in black.

Detail showing pins at neck,  bust point, and armhole.

Then the muslin also gets a little preparation.  (Continued behind the cut)
The muslin is sized based on the form measurements - full torso length x chest arc (from center front at the bustline, on top of the bridge, to the side seam) plus four inches in both length and width; the  back is the same, except with the back measurements, of course.  Selvage edges should be removed and the grain corrected if your fabric is off grain, which muslin often is.  Then the center front on the muslin has a 1" allowance folded and pressed, and a temporary neckline cut in to help get things to lie flat as you start.  It's also worth noting that you only drape one side of the body, so the muslin should be prepared accordingly;  I am choosing to do the left side (mostly because I'm left-handed).

The prepared muslin.

One thing that differs between my old class notes and the book's instruction was where the horizontal crossgrain line on the back goes - the book put it a set number of inches from the neck, where my instructor had us continue the bustline across.  I kind of wish I'd gone with the class note on that one, but I didn't.

Now - finally - the muslin for the front goes on the form!  Pin it at the center front neck, center front waist, and to the tape at the center bust.  The horizontal crossgrain line should line up to the bustline, naturally.  Carefully smooth the fabric over, and pin at the bust point.

Finally, Marie sees fabric.  And pins.  I don't envy her.

Gently smooth the fabric up from the bustline to the point of the shoulder and pin it; it should lay smooth and flat.   Then, being  careful not to cut too far in, clip at the neckline until it lays flat and smooth there as well; pin where the shoulder seam meets the neck.  Clip up from the bottom of the drape to the bottom of the waist tape to release stress; smooth and pin to the princess line (i.e. the seam).

The neck and center front waistline

 The drape is then marked at key points before moving on - the bust point, 3/8" below the CF neck, along the neckline curve, the shoulder/neck intersection, the tip of the shoulder, mid armhole at the pin in the form, and center front at the bottom of the waist tape.  These markings are important when converting the fabric into a paper pattern.  Now comes a tricky bit:  pin in a tiny, tiny tuck - about 1/4" total or a 1/8" depth tuck - at the place the pin is in the form at the front of the armhole.  This gives wearing ease and without it, the person wearing the finished garment would not have enough room to move their arms about properly.

Smooth the fabric around the side of the form to just past the center seam; since this is a one dart bodice and all the dart intake will be at the waist, the crossgrain line should  be sloping down at the side seam.  Pin at the armhole depth pin on the form.  Smooth the muslin down the side seam and pin at the waist tape.  There should be a fairly large fold of fabric sticking out below the bust point; this will become the dart intake.  Mark the side seam on the muslin; most forms have hand-stitched side seams that stand up a bit, so you can make a rubbing with the side of a pencil tip.  Remove the pin from the armhole ease tuck.  Measure 1/2" back from the armhole pin and mark; draw a new side seam from the mark to the side waist. This also adds wearing ease.

Now is a good time to trim away some of the excess fabric at the  top, bottom, and armhole.

Pin another 1/4" ease tuck just in front of the side seam; smooth fabric over to the side seam, clipping up from the bottom as you go to release tension and keep the fabric smooth.  Pin; mark the other side of the fabric at the princess line.  Unpin the bottom of the princess seam on the center front side; tuck the dart intake in, with the fold of fabric going towards the center front, then repin, this time catching only the fabric and not the form.  Pin along the dart leg, being careful not to pin it to the form.  Unpin the other side of the princess seam; the front should be free along the waistline from the side seam to the center front.

Turn your seam allowances under at the side and shoulder seam; finger press them, and repin, being careful to use the redrawn side seam.  FINIS!  Or well, the draping portion for the front is finished, at least.  There are a bunch more things to do before we're actually done.

The completed fabric drape for a one dart front bodice.

Next we'll drape the back.  Then, those fabric pieces will get converted into a paper pattern.  That pattern will get cut and sewn; any changes - and there WILL be some - will get marked on it and then transferred to the paper pattern.  In theory, a second toile should be cut and fit to check the corrections but I'll only do so if they're extreme; I would be more inclined to do so if I was fitting a human, as we are notoriously asymmetrical.  (Even Marie may vary a bit from side to side, since canvas dress forms are partially made by hand, but people can be pretty lop-sided.)  Then the other sloper pieces get made in the same fashion; then the completed patterns will be transferred to tag for posterity.

It's a lot of work to do it right, but it's worth it.