8 August 2019

Jessa: Prepping the pieces and sewing the darts

Welcome back to another Jessa sewalong post. It's Nikki here, Product Manager for Team Tilly, and today I'm going to cover the next few steps in the adventure that is sewing the Jessa trousers and shorts - prepping the pieces, AKA interfacing the waistband, zip facing and optional faux pocket flap, staystitching the relevant pieces, and sewing the darts.

Need to catch up on the previous sewalong posts? Check out our dedicated sewalong page to make sure you're up to date! 

I always find there's something so satisfying in the prepping steps and doing those first few stitches on a new project. These steps make sure your cut pieces will behave properly when you sew and wear your finished garment. It might be tempting to skip the interfacing and staystitching and actually get on with the sewing (I know I did this in my early sewing days!) but I promise the next few steps will help support your pieces and will stop them from stretching out when are sewing or when you actually wear your finished trousers or shorts. Your future self will thank you.

 Ready? Ok let's jump straight into...

Tilly and the Buttons - Jessa trousers jeans shorts sewing pattern


There are loads of different types of interfacing out there, which can make it overwhelming when it comes to choosing one for a project. I usually opt for an iron-on woven interfacing as it's easy to apply and I find it gives the best results for most projects I sew. It's important when choosing your interfacing that you pick something that is a similar weight to the fabric you are sewing with. For this pink denim pair of Jessas which are featured in the sewalong, I used a medium weight woven interfacing as it was a good match to the weight of the fabric.

Tilly has written a blog post which covers the different types of interfacing if you want to do some further reading :)

You will need to interface the back wasitaband, both front waistband pieces, zip facing, and faux pocket flap if you are sewing one. You need to apply the interfacing to the wrong side of the fabric - the purpose of interfacing is to secretly add structure and support to the garment and isn't intended to be a fashion statement!

Tilly and the Buttons - Jessa trousers jeans shorts sewing pattern

Use the same pattern pieces you used to cut your fabric to cut your interfacing. The back waistband needs to be cut on the fold to get the correct shape. You only need to cut one fly facing and it needs to be cut with the glue side - the rough-feeling side - facing down.

Lay the interfacing pieces over the wrong side of the cut fabric pieces, glue side is facing down. If you run your fingers over the interfacing, the glue side will be rough and bumpy whereas the non glue side will be smooth. Make sure the glue side is against the fabric and not facing up towards your iron otherwise you'll have to press pause on your project and clean melted glue blobs off your iron (fun rating: 0/10).

Hold a hot iron, steam turned off, over the interfacing pieces to fuse them to the fabric. I picked up a great tip on this year's Great British Sewing Bee where Patrick said that you should place the iron on the interfacing and count to five, before you carefully pick it up and move it to another section. Try to avoid moving the iron as if you are ironing a shirt as the glue can get all squidged up.

To protect the interfacing from too much heat or moisture, you can place a pressing cloth (a piece of muslin or a tea towel will work) between the surface of the iron and the interfacing if you like, or just make sure there's no steam and the iron isn't too hot. If you are sewing with corduroy or velvet (mmm...), you can use the same fabric as a pressing cloth, right sides together, to avoid squashing the pile.

Tilly and the Buttons - Jessa trousers jeans shorts sewing pattern


The next step on our list is to staystitch the waistlines on the front legs, back legs and waistband facings (uninterfaced back and front waistbands). As these pieces are curved, staystitching helps to stabilise these pieces and keep them from stretching out of shape as you handle the fabric and sew it.

Despite having a slightly technical name, staystitching is actually really easy to do. For each piece that needs to be staystitched, sew a line of regular stitching (2.2-2.4mm long stitches) 10mm (3/8in) away from the edge. You don't have to backtack at either end - hooray!

Tilly and the Buttons - Jessa trousers jeans shorts sewing pattern

Sewing the darts

Now we're ready to sew out darts on the back legs. These darts will help create a nice shape over your booty.

Fold the fabric, right sides together, so the dart lines you have marked on the wrong side of the fabric are visible. Manoeuvre the fabric so the dart lines are on directly on top of each other. I like to do a couple of things to make extra sure the darts are totally in line with each other.

Firstly, I snip into the fabric a couple of millimeters at both ends of the dart legs, so I can easily line up the snipped fabric and therefore the dart at the edge. Once I line up these snipped edges I then
put a pin horizontally across the dart point - this really helps to anchor the shape of the dart. After this I pin vertically through one dart leg, and make sure that the pins are also exactly going through the dart leg on the other side. If they're not, I carefully move the fabric until it is all lined up and the pins are running exactly through the lines on both sides of the fabric.

We'll be sewing from the raw edge to the tip, so point the pins towards the raw edge, most of the fabric to the left of the pins as shown, so you can easily pull the pins out as they're approaching the needle.

Tilly and the Buttons - Jessa trousers jeans shorts sewing pattern
Tilly and the Buttons - Jessa trousers jeans shorts sewing pattern

Starting at the edge of the fabric, backtack and then stitch, following the marked dart line. Once you get to around 10mm (3/8in) away from the tip, change the stitch length to 1mm and pivot the needle to sew the last few stiches along the very edge of the fabric, as shown in the picture, without backtacking. The slight angle at the end helps to smooth out the end of the dart and the tiny stitches secure the ends without having to tie the threads together as you usually would when sewing a dart. Tilly showed me this tip recently and I've been sewing all darts like this since and have been getting great results. All that's left to do is snip the threads and press the dart towards the centre back.

That's everything for today! In the next post I'll talk you through how to sew the pockets and optional faux pocket flap. I love the pockets on the Jessa trousers and shorts so I'm really excited to talk about them. In the meantime, good luck with all your sewing. Don't forget to share progress shots with us on Instagram using the hashtag #SewingJessa so we can all see what you are making.


Photos: Jane Looker
Models: Suzanna Hopkins and Alice Irvine
Pink and white denim: Gifted from Higgs and Higgs
Teal corduroy: Gifted from Like Sew Amazing