There are many ways to finish bra cup seams and I love experimenting with different techniques. Most of the time I line bra cups with a sheer lining because I love the way lining feels and it’s an easy, neat way to hide cup seams. You can even line the insides of foam cups if the seams are bothering you.
But what if you don’t want a lining? Enter seam tape!
This is my favorite way to cover and neaten foam cup seams, and it’s also a common treatment for ready to wear bras that don’t have a lining, both foam and non-foam. I’ve had a lot of questions about how I make seam tape for my foam bras (like this one) so today I’m going to show you! This weekend I was working on a new bra and I shot a spontaneous video to show you exactly where this mystery tape comes from, and how I use it.
Hilarious video note: before anyone shouts at me, I realized after I finished I was pronouncing “tricot” wrong. It’s one of those words I often write but rarely say out loud. I’ve heard some (American) sewists pronounce it “TREE-coh” and others “tree-COH” but never “tree-COOO”.
I don’t buy premade tape but cut it from sheer tricot, which can go by many names. What you want to look for is any kind of sheer nylon lining. I don’t know of any sources where you can buy tricot tape that’s wide enough to fold into thirds and still cover the seam, but why buy premade tape when cutting your own is so easy? I use the same tricot to line cradles, bridges or cups, so I always have some extra to cut out seam tape. It takes me all of a couple minutes with a rotary cutter and a ruler!
Sheer cup lining: Bra-makers Supply, Blackbird Fabrics (what I often use)
15 denier tricot: Sew Sassy, Fabric.com, and many many more (Google it! it’s also called nylon chiffon by some retailers)
40 denier tricot: Sew Sassy
Note that 40 denier tricot is more opaque and a little bit weightier than 15 denier. It can be easier to work with if you dislike sewing sheer nylon, and it makes a suitable cup lining or seam tape material.
In case you were wondering, the bra in the video is a new pattern! I’ve been taking my sweet time refining this pattern, and I’ll definitely be showing you more about it in the New Year. It’s also the bra I was using for my second dyeing video, which I promise will be coming soon. I made a big mistake when filming (I chopped my head off!) and had to go back and refilm.