Drafting Class: Day 2 (Dart Manipulation: Slash and Spread)

Before I go over today’s lesson, I don’t think I need to remind you that I’m a rank amateur. I just think it’s fun to share what I’m learning. I’ll try to do this at least once a week. It helps me remember what I learned and might demystify it for others. Plus, if I’m doing it wrong, then the whole blogosphere can let me know.

So, dart manipulation is something I’ve heard about dozens of time online, but never had a clue really about how to actually do it. Or why I would do it. Today, we learned how to do it with the slash and spread method.

There are six places you can place a dart. I can’t find my handout, so I’ve got this page scanned from my Japanese Pattern Drafting book (I rue the day I posted it, lol. I should have waited until I got all three volumes. I paid like $20 for mine and now they are going for over $100.) Here’s a PDF scan001

dartsOn the first page at the top, you can see the six locations identified for darts. Which all have names.


We start with the one dart bodice sloper and trace it onto pattern paper.


So, I want to move the lower dart to up to the neck (F)


First, I mark my bust point by putting the pattern paper on my sloper (it’s the purple asterisk)


Draw a line from the BP to the Center Neck.


Also, draw a line from the BP to to tip of the original dart.


Slice through both lines removing the section.


Rotate the original dart closed, but, don’t overlap at the waistline. Tape it down.

Congratulations my friend. You’ve moved a waist dart to the Center Front Neck.

We did this today for all the darts (click to enlarge and read what the dart is called)


After that, we worked on adding seam allowances to make this an actual pattern. 1/2 inch for straight lines and 1/4 inch for curves (on a full scale we would add 1 inch for straight lines and 1/2 inch for curves).


Next Tuesday we’ll be doing the pivot and slide method. At some point over the weekend I’ll make a point regarding seam allowances and the bust point. But, I’m sleeeepy πŸ™‚



  1. Girlfriend, from the blogging community, thank you so much. You just made that crystal clear! Sew wish I could be there in class with you.

  2. *hand raised*
    Miss Cidell, what would be the benefit of moving the dart to the neckline? Is it for fit, or just visual interest?

    ps my tuition check is in the mail πŸ™‚

  3. Hi
    I’ve just started lurking, and I want to thank you for this. I like knowing how things are done. Now if I would clear enough room to get back to sewing… That’s the thing about knitting; you don’t need a flat surface so much.

  4. Thank you for sharing, when I ever I’d hear and/or read about dart manipulation, my mind would just shut down…lol Again Thanks, now I have a better understanding. Looking forward to more class reviews.

  5. cool. the slash and spread i understood from reading one pattern drafting book i have. but the pivot and slide, i tried and tried and tried and i still don’t think i got it down a 100% so… if you so have a tutorial for that, it’ll be much appreciated =)

  6. Thanks for the information. We need more details on pivot method of dart manipulation.

  7. When I was a teenager my breasts developed early and I was very self conscious about it. Marilyn Monroe and Jayne Mansfield were popular but I wanted to look like Audrey Hepburn, and years later, Twiggy. In the 50s bust darts horizontal from the side seam were on everything, it seemed like. The darts were little arrows pointing to what I didn’t want emphasized and their layers of fabric under the bodice were visible because my breast tissue was under them, pushing them out. By the second half of the 60s the base of side seam bust darts moved down to the waist or slightly below and it was a huge improvement. Then tops without any darts, made of woven fabrics, not knits, got popular. Some fit me but most didn’t. Many sewers asked for advice about how to manipulate the patterns so a bodice without darts could be made to fit a busty figure. Not until about 10 years later did I see ideas about pivoting pattern pieces to answer this question.

  8. Wow that was unusual. I just wrote an very long comment but after I clicked submit my comment didn’t show up. Grrrr… well I’m not writing all that over again.
    Anyway, just wanted to say superb blog!

  9. Correct me if I’m wrong, but isn’t this the pivot and slide method? slash and spread is the one where you have to cut it into pieces, and well spread it out no?

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