Anything beyond straight stitch required that you install a clunky attachment which moved the fabric in various ways to accomplish the zigzag, buttonhole, blind stitch or decorative stitches you wanted.
We don't have to use any of these today if we don't want to, but they are actually really fun to use, and are quite ingeniously designed.
(All the attachments I'm showing are for low shank machines so would fit the Singer 66, 99, 15-91, 201, 221, and 222 among others.)
First up is not really a sewing attachment, but works with a sewing machine. It is the Automatic Pinker (as opposed to a similar hand cranked version.) If you like to pink your yardage before washing it prior to sewing, this will accomplish it quickly and easily. Theoretically you could use it to finish seams, although I'd probably run the raw edges through here before sewing the seams, to make it easier.
Here's what I believe is the oldest of the Singer buttonholers (as far as I know, anyway.). It doesn't take cams like the later Singer Automatic Buttonholer, but with this attachment you can make adjustments for your length of buttonhole, stitch width, and width of the buttonhole opening. You can "fine tune" it to get just the size you want.
The blind stitch attachment is really a game changer for hemming on a straight stitch machine. It makes perfect blind hems quickly and easily.
This is a very early zigzagger, and doesn't do any fancy stitches. But if you have a Featherweight, this fits right into your case, and is no bigger than a ruffler foot.
For more zigzag options, you have the Singer Automatic Zigzagger which does beautiful decorative stitches. It is big and clunky, because it holds a large cam for the different stitch patterns.
There are sixteen different stitch patterns in all, although only four came with the zigzagger and the others were sold separately in sets of four.
It's amazing what beautiful stitches you can make on a Featherweight with the Automatic Zigzagger.
