how to calculate amount of material for darts in costume design
Answers
Answer: On your paper pattern, find the highest point of the shoulder. This is basically the front neck edge. From the highest point of the shoulder, measure to the level that the bust dart apex/tip is. If it helps, draw a line perpendicular to the CF that intersects with the dart endpoint to establish and even level
Explanation:
Explanation:
When you look in Pattern-making books they usually have a table of standard measurements including either the bust dart width, or it's angle in degrees. These "standard measurements" are for a B-cup, which means that if you are not a B-cup, you have to draft the pattern and then do either a Small Bust Adjustment or a Full Bust Adjustment.
But how do they get these numbers? They seem to have nothing to do with the rest of the measurements. But there is always a formula. It just takes a bit of working out.
What is a bust dart's function? As I see it, a bust dart is there to make the longer front pattern piece match the shorter back pattern piece at the side seam. The front pattern piece is longer than the back one because it has your bust to go over and the back doesn't.
So to find out the bust dart's width at the side seam,
you measure your front from the neck point the red dot over the apex (the green dot on the drawing), and thence straight down to your waistline = F; (this measurement is the orange line in the picture)
then measure from the red dot down your back to your waistline = B; (this is the red line)
subtract B from F and you have your bust dart width, which is the difference between your front bodice length, and your back bodice length.
Now for a little trigonometry. Scientific calculators at the ready!
We'll split the bust dart into two equal parts so that we have two right angle triangles:
The difference between my front measurement and my back measurement is about 2 cm (halved to 1 cm for the split triangle), and the side dart length is about 13 cm on me.