Customizing your pattern is one of the many benefits of choosing to sew your own clothing. The Simple Box Top offers simple built in methods for customizing your garment fit in terms of sleeve width (sleeve opening) and overall garment length.
Your pattern will have "slash and spread" dashed lines on your pattern. You can simply adjust the width of your sleeve by cutting through the "slash and spread" line and uniformly adding space or removing space. You can maintain the total height of the original garment by doing the opposite adjustment to your bodice "slash and spread" line. For instance, if you increased the width of the sleeve, you may decrease the length of the bodice by the same amount to maintain the same overall garment length.
Adjusting Sleeve Width
Find "Slash and Spread Line (for customizing sleeve width)".
Cut across line:
Prepare a scrap strip of paper wide enough to make your desired adjustments.
Tape to one piece and measure amount you would like to add to sleeve width (or height depending on how you think of it). I am adding a half inch in the picture. Make sure line is perfectly parallel to slash line.
Notice the half inch added below parallel to slash line:
Now bring the two pieces back together and tape, leaving the 1/2 inch added space. This will add more room to the sleeve for desired preference on fit or design. This adjustment will add length to your garment. You can either leave this and achieve a longer garment, or counteract this change by adjusting bodice height (continue reading).
Adjusting Garment Length
Find "Slash and Spread Line (for adjusting garment length"
You may add/remove length based on your preference of final garment. This tutorial will depict removing length as an example. Draw a 1/2 inch line parallel to slash line (either piece works fine).
Note the half inch line drawn parallel to slash line.
Join cut edge to new drawn line and tape together.
Slash and Spread techniques are utilized for adjusting many different types of clothing patterns to achieve different looks as well as sizing adjustments, it is a fantastic tool to have in your back pocket to make sizing adjustments on many types of garments without changing the general shape of a garment. You can slash and spread to create gathers, puffy sleeves, flared sleeves, oversized looks without changing necklines, and many many more options!