If you’re making the Frida Shirt sewing pattern, you’ll notice a lovely box pleat on the back of the shirt. This is a classic detail on traditional shirts, creating a relaxed silhouette with a little extra room for movement.
In this tutorial, we’ll show you how to sew the Frida shirt box pleat neatly and accurately. It’s a simple step once you understand the folding order, and it makes a big difference to how the back of the shirt sits.
What is a box pleat?
A box pleat is created when two folds of fabric are stitched and pressed toward each other on the wrong side (or inside) of the garment. Not to be confused with an inverted box pleat, where two folds are pressed towards each other on the right side (or outside) of the garment.
On shirts, a box pleat:
Adds ease across the upper back
Improves comfort and movement
Creates a traditional tailored finish
In the below video extract from our online workshop Learn to Sew a Classic Shirt (featuring the Frida shirt sewing pattern), Tilly demonstrates exactly how to fold, press and stitch the pleat so it stays crisp, neat and centred.
Your pattern includes two pairs of pleat lines, marked near the top of the back bodice (along the yoke seam).
Transfer these lines accurately to the wrong side of your fabric. Precision here makes all the difference.
Step 2: Fold and pin the pleats
Working on the wrong side:
Fold the fabric right sides together to bring one pair of pleat lines together.
Pin exactly along the marked lines.
Check both sides to ensure the pin sits precisely on the marked line - adjust if needed.
Repeat for the second pair of pleat lines.
Step 3: Stitch the pleats in place
Take the fabric to your sewing machine.
Stitch along each short marked line, back tacking at both ends.
If needed, lower the needle into position using the handwheel before starting.
These short lines anchor the pleats at the top.
Step 4: Press towards the centre
Move to the ironing board.
From the wrong side:
Press both pleats towards the centre back.
On the Frida pattern, they won’t reach the exact centre back notch - there should be a gap between them.
Pin in place if they don’t stay flat after pressing.
Good pressing gives a professional finish - you'll thank yourself later!
Step 5: Tack across the top
To secure the pleats before attaching the yoke:
Set your machine to a long stitch length (4–5).
Tack (baste) horizontally across the pleats, about 10mm (3/8in) from the raw edge.
This line of tacking holds everything neatly in place for the next construction step.
And that’s your box pleat complete!
Taking a moment to press the folds carefully will help the pleat sit beautifully on the back of your Frida Shirt, giving the shirt its relaxed shape and showcasing that classic shirtmaking detail.
If you’d like extra guidance while sewing your Frida shirt, our Learn to Sew a Classic Shirt online workshop walks you through every step of the process – from choosing your size and making fitting adjustments, to sewing details like collars, cuffs, plackets and more.
The workshop includes the Frida sewing pattern and step-by-step video lessons, so you can sew along with confidence and build your shirtmaking skills as you go.
Happy sewing and make sure to share your Frida shirts on Instagram using #SewingFrida!
Getting a great fit is one of the most empowering parts of sewing your own clothes. In this post, we’ll walk through how to choose your size and approach fitting for the Frida shirt sewing pattern, so you can sew with confidence from the very start.
In this post, we’ll cover:
How the Frida shirt is intended to fit
Whether you need to make a toile (mock-up)
How to take your measurements and choose your size
Common fitting adjustments you may want to consider
Extra resources for more in-depth fitting help
The good news? Frida is relatively easy-fitting, so in most cases only minor adjustments may be needed. Hooray!
How is the Frida shirt designed to fit?
Frida has a modern, boxy silhouette inspired by menswear. It’s deliberately relaxed and easy to wear.
Design features that affect the fit:
No darts – it’s intentionally loose-fitting
Sizes 7–15 (UK 18–34) include extra length at the front to accommodate a larger bust
Dropped shoulders, with armhole seams sitting lower on the shoulder
Slightly forward shoulder seams as a design feature
Short sleeves finishing above the elbow
Long sleeves finishing slightly past the wrist
Choice of cropped length (low waist) or hip-length (low hip) hem
There is approximately 35cm (13in) of ease at the full bust, so you have a little wiggle room if you’re between sizes.
However, try not to over-fit this pattern. Frida is designed to feel relaxed - embrace the easy, modern shape.
What sizes are included in the Frida sewing pattern?
Whether you buy Frida as a printed or PDF pattern, there are 15 sizes included, from UK 6-34 / US 2-30 / EUR 34-62.
Sizes UK 6-16 (TATB sizes 1-6) and UK 18-34 (TATB sizes 7-15) have been drafted, fitted and graded separately to create a better fit. The latter sizes account for a different set of proportions with a fuller bust (dressmaker's D cup as opposed to B cup in the smaller sizes) and to allow a bit more room at the waist.
Do you need to make a toile?
A toile (or muslin) is a practice version sewn in cheaper fabric to check fit and test adjustments before cutting into your main fabric.
Normally, it’s a good idea to toile a pattern you haven’t made before. But because Frida is loose-fitting, you could skip this step if you prefer.
That said:
Consider making your first version in a more affordable fabric
Tilly and the Buttons patterns are drafted for a height of 5’5”–5’6” (165–168cm).
If you are taller, shorter, or have a long or short torso, you may want to lengthen or shorten the bodice using the lengthen/shorten lines marked on the pattern.
When adjusting the bodice:
Make the same change to the front bodice, back bodice and button stand
Redistribute the buttonhole markings so they remain evenly spaced
This ensures the placket, pleats and cuff align correctly
The finished underarm length (including cuff) is 43.5cm (17 1/8in).
Compare this to your arm measurement, remembering the sleeve starts lower than your armpit due to the dropped shoulder. You may want it a couple of inches shorter than your exact arm measurement.
For small changes, use the lower lengthen/shorten line. For larger adjustments, split the change between both lines.
Grading between sizes
If your bust, waist and hip fall into different sizes:
Use your bust size at the top of the side seam
Blend smoothly to your waist size at the second notch
Blend again to your hip size at the hem
Redraw the side seams on both the front and back bodice pieces to create a smooth line.
Use your bust size for the remaining pattern pieces so everything matches correctly.
If you’d love friendly, step-by-step guidance, and the reassurance of sewing alongside Tilly Walnes, the Learn to Sew a Classic Shirt online workshop takes you through the entire process from start to finish.
You’ll be guided through:
Choosing your size with confidence
Making simple fitting adjustments, if needed
Sewing shirt details like collars, stands, plackets and cuffs neatly and accurately
Building skills in a calm, structured way
The workshop includes the Frida sewing pattern in the full size range, so you have everything you need in one place - no extra purchases required.
If you’ve ever felt hesitant about sewing a button-up shirt, unsure about fitting, or intimidated by collar construction, this workshop breaks it down into clear, manageable steps - helping you sew a beautifully finished shirt you’ll feel proud to wear.
Ever wanted to sew your own classic shirt but felt put off by collars, cuffs and buttonholes? Meet Frida - a timeless, relaxed-fit shirt sewing pattern designed to help you build real shirt-making skills while creating a wardrobe staple you’ll love to wear.
With its boxy silhouette, dropped shoulders, and beautifully classic details, Frida strikes the perfect balance between polished and easy-going. Choose between short sleeves or long sleeves with cuffs and plackets, plus a hip-length or contemporary cropped hem. However you style it, Frida is endlessly wearable.
But that’s not all, we’ve also launched our Learn to Sew a Classic Shirt online workshop to guide you step by step through making Frida. Whether this is your first shirt or you want to refine your technique, this workshop is designed to build confidence and help you sew with clarity.
Designed for improvers, the Frida shirt sewing pattern helps you master classic shirt-making techniques in a clear, approachable way - with beautiful results.
Here’s what makes this shirt pattern so special:
Everyday relaxed fit you'll reach for on the daily
Button-front opening with impressive two-piece collar and stand
Box pleat and lined yoke at the back for a beautiful finish
Choice of casual short sleeves or long sleeves with fancy plackets and cuffs
Two hemline options to suit your style
Optional statement curved patch pocket
Available in 15 sizes (UK 6–34 / US 2–30 / EUR 34–62 / AUS 6–34)
Printed, PDF (with layered, projector-friendly files), or even a bundle format for the best of both worlds!
Frida is a versatile shirt pattern you’ll return to again and again - perfect in crisp cotton poplin, soft washed linen, drapey viscose, or classic chambray.
Learn to sew with our online workshop
Fancy sewing the Frida shirt without second-guessing yourself? Like the idea of a friendly teacher holding your hand through each step?
Here’s what our workshop students have been saying:
"Tilly is fantastic at explaining the instructions in her videos and keeping them extremely clear and easy to follow. Highly recommend to try her online workshops if you haven’t already, she holds your hand all the way, giving me the confidence to have a go." - Judy
"This is the first significant garment I have ever made and I'm so impressed with the result – all down to such a good tutorial. Tilly made every step so straightforward – easy to understand and to copy her instructions... I strongly recommend anyone who wants to take up sewing but is nervous about starting, to take the plunge and get an online workshop." - Myra
"This course was brilliant! I am new to sewing and wanted in-depth easy to understand instructions and this is exactly what I got on the course... I have learnt so much, fallen in love with sewing and discovered my happy place." - Erica
Pattern formats & sizing
The Frida shirt sewing pattern is available in two formats:
Printed pattern – Delivered to your door with a beautiful full-colour instruction booklet and durable pattern sheets
PDF pattern – Instant download to print at home (A4/Letter) or at a copyshop (A0), including layered sizes and projector files
Frida includes 15 sizes (UK 6–34 / US 2–30 / EUR 34–62 / AUS 6–34), and our signature step-by-step photo instructions will guide you every step of the way.
Order the printed pattern and receive a beautifully packaged envelope for your sewing stash. Choose the PDF for instant access and the option to print only the sizes you need.
We love seeing your handmade creations. Share your Frida shirts on Instagram using #SewingFrida and tag @TillyButtons - we can’t wait to see your take on this classic shirt sewing pattern.
If you love sewing your own clothes but feel stuck when it comes to fit, you’re not alone. Fitting is one of the most challenging parts of dressmaking, and it’s something we’re asked about again and again. From gaping necklines to pulling across the bust, many sewists tell us the same thing:
“I don’t know where to begin.”
“I find fitting overwhelming.”
“Bust adjustments intimidate me.”
“I want a calm, logical way to understand what’s going wrong.”
That’s exactly why we've teamed up with professional pattern cuttern and teacher Kate Roberts to create Bodice Fitting for Home Sewing, an online workshop designed to demystify fitting and help you sew clothes that feel comfortable, balanced, and made for your body.
Watch the trailer for Bodice Fitting for Home Sewing:
