This tutorial will demonstrate how to lower the armhole which will add ease across the front & back and increase the sleeve head width.
Alteration achieved – lower the armhole 1cm.
PATTERN PIECES NEEDED – A Front / B Back / C Sleeve
FRONT A
Place a piece of paper underneath the FRONT A so that you have enough paper underneath the armhole and side seam.
At the armhole, measure 1cm down from the side seam and mark.
Using the images below as guides:
- At the shoulder seam, draw the 1cm seam allowance across the shoulder.
At the front neck curve, measure 1cm and mark a dot (our red cross). Where the two lines interconnect this is the shoulder neck point SNP.
Draw a 14cm vertical line from the SNP parallel to the CF edge.
2. At the sleeve edge and on this line, bring out the armhole 0.6cm
OPTION 1 (shown in drawing) – if you happy where your shoulder sits – draw a smooth line from the shoulder edge to the new measurement at the armhole.
OPTION 2 (not shown in drawing) – if you have a wider cross shoulder and would like some extension on the shoulder – extend the shoulder seam out 0.6cm draw the line from the shoulder to the new measurement at the armskye.
3. Continue to new armskye shape through to the new lowered armhole. This should resemble an “egg” shape.
BACK BODICE B – Repeat on the back bodice.
SLEEVE
Place a piece of pattern paper underneath the full sleeve pattern piece.
On the front sleeve side (this is the left side of the pattern piece), draw a line 1.5cm down from the notch. Extend out 0.6cm.
Draw the new front side sleeve shape from the top of the sleeve, connecting through the 0.6cm measurement and to nothing at the sleeve seam.
At the sleeve underarm seam on the front side, extend out 0.6cm and redraw the sleeve seam down to nothing at the hem.
Repeat on the back sleeve.
NOTE – the sleeve is possibly going to need more easing into the sleeve hem. Any extra ease gained needs to be eased into armhole.
Should you have any questions or need additional support, please don’t hesitate to contact us at hello@theavidseamstress.co.uk
Should you just wish to increase the ease in the bicep, see our tutorial here.
The Avid Seamstress 
It would be helpful if you described what sort of body variation this adjustment is required for.
I have big arm and bigger bicep (I am petite sewing F/G cup), with wide back and narrow front, forward shoulder adjustment. I normally need to lower and extend armhole (especially on back because I need bigger sleeve than bodice), but shorten on front and sleeve head while lengthening back. The muscle that connects from arm to bust is well developed, and I usually need to scoop front armhole out more, not widen it, while I have to widen back armhole. While I can make some adjustments on pattern, the only way to get sleeve and armhole to fit together and sit right is to adjust muslin on body.
Hi Karey,
This is great information and shows how different our body shapes are. This is a general adjustment done for those that only need to make these adjustments and none other – again visible when fitting the toile. If anyone needs more assistance in making further adjustments we are happy to help.
Sorry. I didn’t ask clearly. You said lowering the armhole ‘will add ease across the front & back and increase the sleeve head width’. What I was asking is which variation in the person from assumptions about body characteristics built into pattern block require these adjustments?
What we have noticed is that, although the blouse pattern is suitable for a variety of body shapes, anyone that has a slightly fuller bust and wider cross front needs to make these slight adjustments to obtain a better fit.
Thankyou very much. This is really clear for a new sewist.
Thank you Jude, we are always here to help if you need any help.
Hello, is it possible to make this adjustment without lowering the armhole and just creating ease across the front?
Hello Desiree – I think this adjustment would be better for you. It will provide 4cm across the bust and provide a little bit of ease on the bicep :)
https://theavidseamstress.com/2021/06/05/theblouse-adjustingthebicep/