By hand! Google "ladder stitch" add I believe that is the answer. Not all makers use that stitch but the moral of the story is the stitching is done by hand. That being said the quilting lines on the pads are done by machine.
Chiming in late, but I made my gloves with the sewing machine. As long as you take it slow, it's not that hard to sew all the contours around the fingers. (Sewing the half-sleeves onto my flight suit was harder.)