If you have a child with sensitivities to seams (or just want to try a different look!), here is a great way to sew the Mabel puffed sleeve with a long undersleeve and ditch the band!
When using this method, there is no seam against the child's bicep - just a smooth sleeve, with the seam sandwiched between the puffed sleeve and under sleeve.
I chose to make a tunic length Mabel with handkerchief skirt using this method, from a gorgeous tie-dye printed bamboo from Salmon Valley Knits (preorder available until Feb 20th, on many different fabric bases). The puffed sleeves in bamboo have less volume than they would in a more structured knit such as cotton lycra - stay tuned for another sample coming!
NOTE: The normal puffed sleeve/band/lower sleeve combination is a lot narrower in the middle of the arm, in order to hold up the puff. When using this alternate method, you can either use the regular sleeve (for a looser fit through the arm), or you can narrow it as shown below, using the lower sleeve as a guide, for a more fitted look, but still not as snug at the bicep as it would be with the band.
After cutting your sleeves out (puffed sleeve + regular sleeve), place the puffed sleeve on top of the regular sleeve (we could also call it the under sleeve), lining it up at one of the corners as shown below, and place a mark on both sleeves 1/4" up from the bottom of the puffed sleeve. Repeat on the other side.
Sew your gathering stitches on the puffed sleeve as per normal.
Next, place the puffed sleeve as shown below, RIGHT SIDES TOGETHER with the under sleeve, with the sleeve cap pointed towards the bottom of the under sleeve. Pull the gathering threads until the width matches, then tie off your threads.
Making sure the marks on both sleeves are lined up, secure the sleeves together with pins or double sided tape (see further down for more info on using tape). A washable glue stick is another alternative that works - just make sure to let your glue dry before sewing.
Next, sew straight across, from one mark to the other, securing the sleeves together.
TIP: Using Wash Away Wonder Tape is a great way to ensure your gathered sleeve does not shift while sewing it to the the under sleeve. Place it straight across, right above your placement marks. Then stick the gathered edge to it and sew just underneath the tape.
Next, flip the puffed sleeve up, then pull the gathering threads along the top until it matches the sleeve cap of the under sleeve. Tie off the threads so you don't lose your gathers.
Finally, baste your puffed sleeve to the under sleeve around the top and sides. Then you can proceed to sew the bodice together as normal!
If you don't already have the Mabel pattern, you can use code MABELSLEEVE to get 20% off!