Some signs you may need to make a SBA:
- There is unneeded room across the bust
- You have a gaping or drooping neckline
- The toile sits lower at the front waist than at the back
How much extra room do I need to remove?
Work out the difference between your full bust measurement and the bust measurement on the back of the pattern. For example, the pattern measurement is 35″ for a size 10, which let’s say is right for you at the waist and hips, but your bust is 33.5″. This means you need to remove an inch and a half (or 4cm) of room from this area. As the bodice pattern piece is only half of the full bodice however, this means you need to remove 3/4 inch (or 2cm). So the total adjustment you need to make needs to be divided in half to account for the two bodice pieces, and that gives you the amount to increase the bust by. For our example, this is 2cm.
Making a small bust adjustment
1. Try on your toile and mark your bust apex directly onto it using a felt tip. (Your bust apex is usually where your nipples are!)
2. Transfer this to your pattern piece from the toile
3. Draw a line from the bust point down to the waistline (line 1), parallel to the grainline.
4. Draw a diagonal line from the bust point to the upper notch on the armhole (line 2).
5. Draw another line from the bust point to the side seam, about 5cm below the armhole (line 3)
6. Cut through lines 1 and 2, but on line 2 stop when you reach the seam allowance on the armhole. For line 2, cut through the seam allowance on the armhole from the other direction, but leave a small amount unsnipped so you can use this as a ‘hinge’ to move the pattern.
7. Cut through line 3, but again leave a small amount uncut at the bust apex.
8. Draw a line parallel to line 1, at the distance you need to decrease by to the right hand side of this line. (In our case 2cm.)
9. Move the left hand part of the pattern until it sits exactly on top of this line. Tape in place.
10. Line 3 will have shifted to overlap the other sections of the pattern to decrease the area. Tape this in place.
11. To level the waist on your pattern, cut along the lengthen/shorten line on the right hand side of the pattern. Shift this over until it is in line with the waist and centre front again.
12. At the side seam, you may need to smooth out the curve. Simply add some spare paper underneath and redraw the curve in using a pattern master, before trimming off the excess paper.
You may need to adjust the waistline to its original width to make sure the bodice will still fit you. However, most of the time SBA adjustments will fall in between the gathering section, so we recommend just reducing the fullness in this area, instead of adding extra width.
And that's your small bust adjustment done! Next we'll be talking sleeve adjustments!