The following is a special contribution from EmilyKate, a loyal friend-of-Zigzaggers (see her sewing machine reviews here, here, and here). This wonderful and helpful bit of information will be particularly useful for owners of vintage sewing machines that only sew a straight stitch. Find EmilyKate at her blog; and if I may be so bold, I'd like to particularly recommend a lovely post about her grandmother, here -- it's not sewing-machine-related, but her thoughts about the aesthetic traditions that are passed down in families are relevant and touching. Herewith, EmilyKate introduces buttonholers:
Many sewers who use vintage straight-stitch only machines believe they can't use them for making buttonholes -- the needle has to be able to zigzag for that, right?
Actually, it doesn't! Back in the day, sewing machine companies invented clever little gadgets that attach to straight-stitch machines: They clamp onto the garment fabric and wiggle it back-and-forth and side-to-side under the needle, creating the buttonhole. The gadgets, which were called automatic buttonholers, are readily available on eBay and sometimes show up in thrift stores. Some of the brand names they were marketed under were Greist, Singer, White, and Famous. Kenmore also made one for their machines.
There are two types -- one type uses interchangeable templates for different sizes and shapes of buttonholes (straight or keyhole-shaped); the other makes only straight buttonholes the length and width of which are adjusted with levers and knobs. You can pick up either type pretty cheaply on eBay -- expect to pay anything from $5 to $25.
It's important to make sure you buy an attachment that has the correct shank type for your machine. Most vintage machines take low-shank, side attaching attachments, but there are slant-shank variations (for slant-shank Singers, obvisously), and if you have a vintage Japanese-made machine you may need a high-shank attachment. (ed note: See Ed Lamoureux's blog here for more information about shank types.)
If you want to see a buttonholer in action, check out this video I posted on BurdaStyle!