If you've noticed, I don't write many posts on pattern alterations and there are several reasons for this:
1. I honestly believe that sewists especially beginners should be taught the proper way of constructing garments! I know that I'm shortcutting and changing things. But that's because I already KNOW and HAVE a well built foundation...so I know when I can and can't push the boundaries of construction techniques.
2. I don't think I'm a great teacher...before you start to complain...let me explain! I believe that a great teacher can share a technique in such a way that someone can understand it at a very basic level. That ain't me...I wish, but it ain't. Now can I inspire? Yes! Can I encourage? Yes! And can I enable? Yes, with the best of them! *LOL* But teaching takes a special gift that I don't believe I possess...
So it is with much reluctance, hesitancy and many, many disclaimers that I am posting how I make alterations to sleeve patterns to fit my bodacious biceps...shew, that was a long winded introduction! *LOL*
First - measurements:
I measure my bodacious biceps at their fullest point...so skimp on this measurement or be untruthful if you want but you risk having very ill-fitting sleeves if you don't take correct measurements. Personally, I don't care what the number is on the tape measure, what I care most about is the fact that a well-fitted garment actually makes you appear thinner and better looking than something you are stuffing yourself into.
Second - Ease:
The Perfect Fit in the Singer Sewing Series defines ease as, "extra room designed into a pattern or garment for comfort and style. The amount of ease varies from one fashion style to another and is often the key to how the fashion fits. Ease can be adjusted, but avoid over-fitting by removing too much ease."
To me the most important point of making a sleeve alteration is determining adequate ease before cutting up your pattern. For this you need to try on a sleeve that works for you...that is attractive to your figure type and flatters your arms. From the sleeve you tried on, determine how much ease you need/like. Then take the measurement of your biceps, add the amount of ease you want plus seam allowances...this is the final figure you need for determining how many inches to add to the pattern.
Now I use two totally different alterations for long and short sleeves...so I will deal with short sleeves first.
This picture illustrates the fact that I slice the pattern from 1/2" from the top of the sleeve cap through to the hem. I then add the additional inches determined by my formula above. The last step is to true up the hem, because the sides of the sleeve will be higher than the bottom.
By slashing and spreading you do not change the width of the sleeve cap - so it should fit into the armscye without any problems...well that is if the original sleeve cap and armsyce are drafted well...but we're not going there today! *smile* To me this is the easier of the two alterations and it allows me to add enough space to the bicep area and to lengthen my short sleeve to a flattering length for my arms.
Now for long sleeves...
To get my biceps to fit into a long sleeve I have gone through a few gyrations. I have tried the method used by Palmer and Pletsch. I have tried Cynthia Guffeys' method...all with varied measures of success. I finally settled on adding a seam to the top of the sleeve because it allows me to add at the biceps in the simpliest method possible. It also gives me quite a few opportunities for embellishments - i.e., topstitching or inserting piping...and it's become a kind of trademark of my garments.
How do I make this alteration?
**Then I add a 5/8" seam allowance mark to the sleeve cap and another mark at the sleeve hem.
**Two more marks are added - one between the sleeve cap and the bicep easing from the 5/8" seam allowance to the bicep allowance. And the second mark is made after the bicep mark and the sleeve hem, easing from the bicep into the sleeve hem. I use a ruler to make this line.
**I then cut out and sew together the 4 sleeve pieces making two separate sleeves.
Okay, do you have any questions? The blog is now open to questions, comments, clarifications, and other methods and/or techniques for enlarging bicep measurements.
Please feel free to ask questions, if I haven't been clear on anything in this post. Or feel free to correct something that I am advocating if you truly think it's wrong...but I do add the codacil that it's working for me so I'm not about to change...but it if will help someone else, let's add it to the conversation.








