You have to subtract from the back length the measurement of the whole width of the pleat i.e. the width of the pleat when opened. This sounds straight and you may think that the the corrections should be done vice versa, but this is what you have to do, believe me. If bust apex of the garment is too high or too low, change the bust height measurement accordingly. After joining the sleeves to the muslin Sew sleeves. If you needed to make a pleat at the front or the back armscye, fold a corresponding pleat at the front or the back of the sleeve caps.
Join sleeves to the shell.
If the garment is too tight at the back, as in the picture, unravel some of the back seams of the sleeve caps and measure the amount you have to add to your back width measurement. Make sure that the waist seam of the muslin is in place. If it is too high or too low, change waist height and back length accordingly. Be careful not to change waist height and back length with different amount because it might change the direction of the shoulder. Patterns Normally the patterns for a basic sloper are more or less like in picture 1 .