I did do some research on this, and there is a lot of info on the web as to doing sashiko with a machine. I have a Bernina so I looked at those videos. Hints I got included using a cordonnet foot which has a grove in the bottom for the thicker thread, to use a thicker thread on the top and a navy thread in the bobbin as it will blend in with the indigo fabric sashiko is traditionally done on. However, it looks like there are a couple of different stitches to use to get the look of sashiko. One method, involves using a staight stitch but tightening the top tension so the bobbin thread is pulled to the top and that is the thread you see. Triple stitches may be used. There seems to be several ways to get that look. Also some machines have a "hand look stitch" that may look like the sashiko stitch too. So, I think it is best to do a search for "doing sashiko" using the type of machine you have. I plan to look at my manual for my machines and also at the separate foot book I have that explains different techniques.