Updated: Aug 22, 2021
Welcome back dear readers. With the making of the Bodysuit Pattern, the issue of sleeve cap heights arose and so in this topic, I will share the importance of adjusting the Sleeve cap height for different patterns and 2 basic ways to do it.
When we drafted the Basic Sleeve Block, we made a standard straight sleeve with the maximum cap height. The effect of this pattern is a sleeve that hangs straight down when your arm is in its natural resting position. This angle does not permit a wide range of movement and will pull up the garment when the arm is raised.
Depending on the style of garment you are making and its function, it is necessary to adjust the Height of the sleeve cap accordingly. The general rule is that the lower the cap, the wider the range of movement. So for a men's dress shirt, for instance, it has a very low cap to permit a full range of motion and for a formal suit, it has a high cap, for a minimal range of movement, while giving a tailored polished look.
The Sleeve can be drafted from scratch with the cap height you want, or the basic sleeve block can be modified to achieve the same results. I have reasoned out the rule of thirds for deciding the right height of the cap. One-third of a full cap height for a low cap, two-thirds for a medium cap, and finally a full cap height. This requires that you have the full cap height measurement which is the Full arm length minus the Underarm length. Details can be found in the Basic sleeve block article.
Drafting from scratch
This follows the steps as drafting a standard straight sleeve except Line A-C will be the adjusted Cap height and Line E-F will be determined by the length of the Armhole of the Bodice that the sleeve will be attached to.
1. Line A - B = Full arm length Measurement
2. Line A - C = Cap Height Measurement. Draw a guideline from this point on both sides (Bicep line)
3. Line A – D = Shoulder to Elbow Measurement
4. Line A to E / A to F = Front and Back Armhole of the Bodice measurement with ease (add about 0.5inch (1.2cm) to both). Draw straight lines from point A touching the guideline (Bicep line)
5. Line G - H = Split Wrist measurement equally over point B. GB is equal to half wrist, and BH is equal to GB. This should wider than your Hand measurement unless attaching a cuff.
6. Join points EG and FH with straight lines
7. Line I - J = Square a straight line on both sides of point D, touching lines EG and FH. Label as points I and J as illustrated.
8. Draw the Curve of the Sleeve Cap the same as normal straight sleeve, keeping the curves more shallow.
Modifying the Basic Sleeve Block
1. Trace the Sleeve. Here you can decide on the length of the sleeve and the width of the base.
2. Point A to B - Mark the new Cap Height. Draw a guide line from B on either side (bicep line)
3. Point A to C/ Point A to D - Using the Basic Sleeve Block as a Template, pivot the centre of the sleeve block at point A and swivel to touch the bicep line on both the front and back sleeves, tracing the curves of the sleeve cap.
4. Label the base of the sleeve as Points E and F. Join Points E and F to Points C and D.
5. Extend Elbow line to touch the sides and label them as points G and H.