i've stumbled across many sewing peeps, both online and in person, who have a fear of working with leather. having jumped into this material blindly and with both feet, i thought i'd share what i've learned so far with you.
be prepared to get it wrong the first time.
just like the first dress you made or the last seam you ripped, you're going to have to accept a few fails. now, fails in this area do suck a bit more because leather is expensive, so try to find scrap leather to play with before starting that red MJ jacket. some stores will have remnants. if you don't have the garment district at your disposal, try this site.
get the right tools.
hands down the best machine needle i've found is schmetz, they make specifically marked leather needles in sizes 12-18. Amazing Lady hepped me to these. i use 14 for thin leathers, and 18 for the thickest hides. buy a few packs, because you'll want to replace them often! i have a dedicated pair of fiskars for cutting, no need for my fancy ginghers. i like a sharp seam ripper rather than a thread snipper to trim thread ends, i can get closer to the leather without nicking it.
when leather is pierced by a needle, it's not something that can be steamed away. those holes will stay. practice and muslins and lots of patience are your best friends with benefits. now, pinning is a very mean girl that likes to talk about you behind your back. ignore her. double sided leather tape is key when joining pieces together, i cut very thin, small strips; about 1/8 inch wide, and use these strips in place of pins on the WRONG side of the leather. this stuff is much thinner than ordinary double stick tape, you can sew right though it.
can your machine handle the truth?
threadwise, i like coats & clark dual duty cotton/poly, it's strong, not too thick, and i can always find the color i want-- that's important to me, because i play with extreme colors in leather and need way more than the basic black and white heavy duty threads i find in most shops. but play, you might like thread the size of a plywood beam. no judgements here.
i don't know about y'alls new fangled computer-ma-rized machines, but if you've got an old metal vintage job, you're in luck. my 80 pound metal kenmore eats up leather with a grin. when sewing leather on any machine, the tension should be set high (on mine that's a 6), and the stitch length should be fairly long--shorter stitches mean less space between the holes the needles creates, which for obvious reasons ain't good. on mine, no lower than a 5 for length on a straight stitch. i like to use a zigzag stitch when joining leathers on my belts (that's a 4 width & 3 length on my vintage dials).
slow down, partner!
best not to race through a seam on leather like you're sewing cotton. there are too many little hitches that can-- and will-- break your needle and send it flying off into your facial region. (oh, what's that you say? you have one of those computer-ma-rized machines with a needle guard? feh.) the hide of the leather can cause friction with the pressure foot, a little burl on the underside can mess with the feed dogs, the grain of the leather will change and simply not want to go in the direction you're headed, the needle gets pulled the wrong way one too many times and pop! as long as you're taking your time, you'll be fine. also, starting your seams at the very edge of your leather will cause you grief. the material will hitch up before you can begin. start with about a half inch of leather behind the back edge of the presser foot.
you got to know when to hold 'em.
so, your leather says: no thank you, my current plans do not include following the path you are leading. you can reverse the current direction and sew your seam from the opposite direction, that will solve the problem most times. otherwise, a little manual help will do the trick. while running the machine very slowly, give a gentle and constant pull on the back of the material to get it moving, holding the front steady as well. if you & your machine are still working hard after a few inches of seam, try reversing the direction. sometimes, the grain of the leather just wants to go where it wants to go.
papa needs a new pair of shoes!
machine feet! i have learned to love them. i have not, however, found a teflon presser foot that fits my vintage guy. c'est la vie. you may find one quite easily, and it could make the 2 previous paragraphs of rambling completely moot for you. if you have a vintage machine and can't find your proper foot, don't despair-- after my first hour of playing with leather, my machine seemed to build up some confidence and sews like a dream now. or perhaps my machine does not have access to human attributes, and the oils from the hide have just built up? maybe that's not so good? again, i say FEH!
i have also heard of peeps using baby powder; dab some onto the underside of the leather, tap off the excess and go; but as a vintage user who regularly cleans and oils her machine, that starts the JAWS theme music in my head.
what's my type?
if your leather is of the shiny patent variety, you're in for some tears. the shinier the leather, the less it will want to move freely under that presser foot. it would be like sewing your first garment in silk chiffon rather than cotton... just step away from the patent leather, ma'am. go for a nice buttery soft thin to medium weight leather for your first outing. not to mention, if you're sewing a garment rather than say, a belt, you'll want thinner leather for all those seams.
i hope this proves useful... ask away if anything's unclear or unsaid. my best advice: dive in and see what happens!
love, oona & roxie.