Thank you for all your lovely comments on my rose dress! I’m so happy with it!
As promised, here is a tutorial of the way I sew in an invisible/concealed zip, which is my preferred zip finish.
For insertion of an invisible zip, I’d really recommend an invisible zip foot. Some people say they can put them in with an ordinary zip foot, but as the stitching needs to be directly below the teeth for the tape to be invisible on the outside, I don’t think I could get the needle close enough in without the specialised foot. In my mind, invisible zip means the zip is invisible, so stitch placement is important to me! But I have perfectionist tendencies…
I don’t have a machine-specific foot; mine is a generic low-shank foot, which I bought for my old machine, and fits my new machine too! Machine-specific feet can be expensive, so maybe this generic option might work for you too?
The foot has ridges underneath to roll back the teeth and expose the channel the stitching should go in..
So, thanks to that special foot, I’ve always been fine getting the zip into the centre back, but I’ve had the quite the battle over the years trying to figure out how to get the top straight and the inside neat once it’s faced/lined. But I feel I recently cracked it, and this is how I’ve been doing it…
I insert a zip when the left and right back pieces are not sewn to the front at the shoulders or the side seams. They are also not sewn to each other vertically along CB seam; but the zip does go in after horizontal sewing- so the left skirt is already attached to the left bodice, for example.
Placement of the zip is the first thing to figure out. (Everything I say here is for centre back zips on a dress, but the same theory applies for all invisible zips- if you put it in the side seam of a skirt, for example.) Draw your seamlines in with chalk/washable pen, so that you get a cross point of where your finished sewn corner will be. Do this on the right side of your fabric.
Drawing the seam in all the way down the centre back can be helpful with zip placement if you have a 15mm or more seam allowance. (Invisible zips are built for the garment industry’s 1cm seam allowances, and so if you have that size you can just butt your zip tape against your raw edge…)
The teeth of an invisible zip can roll back, and it is under here, in this channel, that the stitching has to happen. This channel is therefore what you need to place on the chalk stitching line you have sewn on your fabric. This next photo is out of sequence, but shows (with the arrow) the area I’m talking about sewing on…
But first we need to sort out where to start the zip at the top! This is what your chalk crosshairs are for: place the top of the zip stop (the plastic square above the teeth) beneath the horizontal line of the crosshairs you marked.
How far beneath the crosshairs is going to depend on the weight of your fabric, and the turn of cloth that will then come into play when you create the corner. You’re looking at putting the zip stop perhaps 1mm below, or even maybe 3mm below for a thick wool. Also, the top of the zip pull usually sits a bit above the zip stop, so these are your considerations. My thinking is that if you do place it a smidge too low, you can always drop the back neckline seam at the end of play…
And this is what I had to do… I was too busy thinking about taking the above photo to realise that this was too low for a thin cotton lawn. But not the end of the world- these things are easily fixed, as you will see…!
If you’re new to invisible zips, I recommend doing the zip up, and sitting the right side of the fabric folded with the seam allowance underneath on top of the non-teeth side of the zip- so you are essentially creating how you would expect it to look when sewn. Pop a pin in to hold it before opening the zip to start “proper” placement. This means that you can be sure you are sewing the correct side of the fabric to the correct side of the zip!
And even now, after years of doing these, I still always do this on the second side of the zip, because it takes five seconds and prevents the silly tangles I have got myself in one too many times…
Once you’ve figured that out, open up the zip and handbaste or pin in place the side of the zip you’re going to work on first, matching your sewing channel with your chalk stitching line. (If you’re always confident with lining up while sewing, you can just pin-baste at the top.)
Insert your needle just at the top of the zip stop (where the arrow is on the photo below), leaving the top of the tape unsewn.
Now you can start sewing the zip in!
I use my finger flat right up against the edge of the foot, as this flattens the teeth out and helps the foot to align and move the teeth properly out of the way for the stitching. It felt scary the first time I did it, as my finger felt uncomfortably close to that sharp needle, but as long as my finger is stationary or only coming back toward me, I know I won’t get stabbed!
Sew down the zip as far as you can- the zip pull will stop you going the whole way. Zip up. See that nothing has caught in the seam that shouldn’t have, and pull the fabric seam, so that you are happy it is tightly sewn, with pretty much no tape showing- this means the zip will be properly invisible in the end. I had to re-sew an inch, where I had wavered away. It was less than a millimetre, but as I said- I like invisible to be invisible and it’s a 1-minute job… (perfectionist alert!)
This is what you’re aiming for:
Now to sew the other side of the zip! If you have cross seams, like I do in the waist on this dress, close the zip and mark matching points on the unsewn side of the zip tape with chalk.
You can use these marks to match up the seams on the other side of the bodice.
This is me checking I’m joining the right sides together…
Open up the zip, matching the cross-seam points, and pin/baste the unsewn side of the zip. Repeat your sewing as before, and finishing with by checking you are happy that the zip is invisible once fully sewn in and zipped up.
Zip? What zip?!
At this point you can sew the centre back seam below the zip. You’ll need to use a normal zip foot to get in close to the bottom of the teeth, while still on your sewing line. It’s fiddly, because of the bulk from the raised teeth on an invisible zip, but take your time and all will be well! I don’t have any pics of this step, because my dress was to be lined and so the order of sewing was different for me…
Although my dress is lined, the work at the top of the zip is the same regardless of whether you are lining or facing, or facing with some bias binding. But I’ll call it “facing” for simplicity’s sake.
Place your facing right sides together at your neckline, and we’re going to get ready to sew the neckline. These next steps are the most important part of how we get the top of the zip flat.
Mark the seamline in the same way as you did at the start of zip insertion, but on the wrong side of the fabric this time. Sew the seam, and as you get to the zip area, hold/pin the loose zip tape out of the way of your sewing line. If you have thin fabric, and the sewing line is therefore close to the zip stop, you can use a normal zip foot to sew this, so you can get your stitching in where you want to to be.
I didn’t mark a chalk sewing line on this photo, sorry…
Turn the garment right side out and zip up. Check your alignment of zip pull, and the top of the neckline matches on both sides.
Mine often doesn’t exactly! This is the point where you find out if putting your zip stop 2mm below the crosshairs was too low… If it is, just go back in and re-sew until you’re happy with it (second perfectionist alert…!)
Once you’re happy, you can turn your work inside out again and lay the facing flat right sides together, so you are covering the zip and matching the raw edges at the centre back. We are going to attach the facing by machine- no handsewing of this for me!
We still don’t sew on the zip tape above the crosshairs- there are two options here, both of which I’ve seen in quality RTW: either pull it to the side and out of the way when sewing, or fold down onto itself so it is below the crosshairs when sewing. Choose one of these, then sew down the centre back seam on the zip tape area, close-ish to the zip teeth.
In England, there seem to be two main makes of invisible zip- and one has a much lighter tape than the other. This, along with the weight of fabric, is a deciding factor as to whether I choose to cut out the portion of zip tape I’ve left flapping around unsewn to reduce bulk in the corner (if I haven’t done the fold down option). Bulk is one of the major causes affecting the way a corner turns and lies flat. Or doesn’t! Which is why we don’t sew the tape above the zip stop, otherwise that will definitely have an unwelcome presence in the corner…
On lighter fabrics, I also don’t always cut the corner of the seam to be turned, as I find it can add weight and stability. But this depends on your fabric, and so is a judgement call for each garment.
Turn the seam right side out, and you have a flat topped/faced zip inserted- and with no handstitching of facings!!
My evil perfectionist inner voice is looking at this zoomed-in photo and telling me one side is not quite as good as the other…!
If your fabric calls for it, you can understitch along the facing now, getting as close as you can to the zip area. I’ve tried doing it before sewing the facing at the CB, but it just gets me in a pickle with getting the top nicely lined up. And I’ve seen quality RTW with the last half-inch of facings not understitched, so I figure it is acceptable practice to do it in this order!
And when the zip is this high, you don’t need a hook and eye: result!
I hope this was helpful. They are my favourite type of zip closure, and if you haven’t used them before, do give them a go!