The Ultimate Supplies Checklist for Sewing Underwear, Swimwear & Gym Wear (Everything I Wish I’d Known When I Started)
Ever bought fabric online, opened the parcel, and thought “this looks nothing like the photo” 😑? Or maybe you grabbed the wrong elastic and spent three hours wrestling with it like it was made of concrete? Been there, done that, got the scratchy bra to prove it.
Hi, I’m Alyona, and I’ve been sewing for as long as I can remember. Back when I was a kid, I worked with a tailor to make a dress for a dancing competition, and honestly? I fell head over heels. There’s something magical about handmade clothes – you can play with fabrics, adjust the fit, mix textures, and create something that’s totally yours. Since then, I’ve been hooked on making my own underwear, swimwear, gym wear, and loungewear.
But here’s the thing – I wasted a lot of money on rubbish supplies when I started. Like, a LOT. And I wish someone had handed me a proper checklist back then, because buying online is brilliant until you realise the “soft stretchy lace” you ordered is actually scratchy sandpaper masquerading as fabric 🙄.
So in this article, I’m sharing my go-to supplies checklist – the exact materials and tools I use on repeat for making underwear, swimwear, gym wear, tops, and all sorts of clothes. These are my tried-and-tested favourites, the ones that actually deliver what they promise. If you’re just starting out (or if you’re tired of surprise parcels that look nothing like the listing), this guide is for you.
Fabric – The Foundation of Everything (Choose Wisely or Cry Later)
Okay, let’s talk fabric. I know some people get proper intimidated by stretchable fabric, but honestly? It’s the easiest fabric to handle, especially if you’re a beginner. Why? Because stretchable fabric is forgiving. Made a tiny measuring mistake? The fabric compensates. Cut something slightly wonky? The stretch will save you. It’s like having a safety net made of elastane 🙌.
My absolute favourite type is four-way stretch fabric – it stretches in all directions, which makes it perfect for underwear, swimwear, gym wear, tops, and even lounge dresses. Here are my top picks:
Spandex Mesh
This stuff is perfect for underwear and swimwear. I love using it to create combinations – like a transparent back with a non-transparent front. It’s super stretchable and gives you loads of flexibility. Plus, it’s brilliant for sportswear because it’s breathable. I often use this spandex mesh fabric to add see-through panels or make the back of gym tops more comfortable and airy, especially on those sweaty workout days.
Four-Way Stretch Polyester
This is my desert island fabric. Honestly, if I could only keep one fabric type, this would be it. You can make literally anything with four-way stretch polyester – bottoms, tops, swimwear, underwear, gym wear, and I’ve even made a few dresses with it. It’s like the Swiss Army knife of fabric. Versatile doesn’t even cover it.
Four-Way Stretch Velvet
Now, this one sounds fancy (and it is), but hear me out. I mostly use four-way stretch velvet for dresses and tops, but also – wait for it – … underwear. I know, I know, velvet knickers sound bonkers, but you can’t imagine how fluffy and cosy they are. Perfect for cold days when you want to feel like you’re wrapped in a cloud. Also brilliant for making socks! The colour options are endless, too 🌈.
Four-Way Stretch Leather Effect Fabric
Want to look like a total badass? This mirrored leather effect fabric looks like real leather but stretches in all directions. Perfect for leggings, gym wear that makes a statement, and even underwear or swimwear if you’re feeling adventurous. I’ve made a few pieces with this and honestly, the “wow” factor is unreal 🔥.
Printed Polyester
This fabric is just fun. First, it makes your projects way less boring. Second, the stretchability is fantastic. Third, you can mix printed polyester with different types of lace, and it looks absolutely gorgeous – especially for underwear. It’s one of the most enjoyable fabrics to work with because the patterns add instant personality.
Interfacing – The Secret Weapon
Okay, this isn’t glamorous, but interfacing is crucial. When you’re working with stretchable fabric and you need to add a neckline, armholes, or a zip (like on my Rubanette Swimwear Sewing Pattern), interfacing stops everything from going wavy and stretching out of shape. It gives that clean, professional finish. Trust me, it’s worth having in your stash.
Lace – Because Pretty Details Matter
Right, there are two main types of lace you need to know about: stretchable and non-stretchable. Let’s break them down.
Stretchable Lace (The Forgiving Kind)
My favourite here is 18cm Wide Nylon Elastic Lace and this Multicolour Elastic Lace that goes in both directions. It comes in different widths – 18cm, 20cm, 22cm, and so on. Here’s a pro tip: measure from the scalloped edge to where your pattern piece ends, and that’s the width you need. Simple as that.
Non-Stretchable Lace (For Adjustable Designs)
Non-stretch lace is brilliant for bras or any design with adjustable straps. Since you can adjust the fit with the straps, it doesn’t matter if the lace itself doesn’t stretch. Plus, it looks gorgeous on both tops and bottoms. Some of my favourite embroidered lace pieces are non-stretch, and they look absolutely stunning – like something you’d find in a fancy boutique, not your sewing room 😂.
Elastic – Not As Scary As You Think
People get proper lost when it comes to elastic, thinking there are a million types. But really, there are only four main types you need for underwear and activewear:
1. Fold-Over Elastic (The Beginner’s Best Friend)
This is hands down the easiest elastic to use. You literally put the fabric in the middle, fold the fold-over elastic over, and sew. No overthinking required. Plus, it comes in endless colour options, so you can match it to any fabric. If you’re just starting out, this is your go-to.
2. Picot Elastic (The Fancy One)
Picot elastic is a bit trickier to sew than fold-over, but the result? Chef’s kiss. It takes your underwear from “homemade” to “boutique-level” in seconds. You can get picot with bigger scallops for a bold look or smaller scallops for something more subtle. Colour options are great too – red, pink, white, black, you name it.
3. Strap Elastic (The Shiny, Supportive Kind)
You know those shiny bra straps that look all professional? That’s strap elastic. It comes in different widths – 8mm, 10mm, 12mm, 14mm – and it’s more rigid than other elastics because it needs to provide proper support. But here’s a fun secret: you don’t have to use it only for straps. I’ve used it to jazz up knickers before. Get creative 🎨!
4. Bent Elastic (The Hidden Support)
This wide elastic usually goes on gym wear to give extra support under the bust, or on swimwear, trousers, and shorts for waist and hip support. It comes in loads of widths – from 2.5cm up to 7cm (the widest I’ve used). I usually hide it inside the fabric for a seamless look.
Hardware – The Little Bling That Makes It Look Shop-Bought
Hardware is all those little rings, sliders, and clips that give your underwear that “I didn’t make this in my living room” vibe. Here’s what you need:
Rings
Rings need to match your strap elastic width. If you’re using 8mm elastic, you need 8mm rings. Simple. They come in white, black, silver, gold, red, pink – basically every colour you can think of to match your fabric and elastic.
Sliders
Sliders also need to match your rings and strap elastic – so 6mm, 8mm, 10mm, 12mm, etc. But here’s where it gets fun: sliders come in different shapes. My absolute favourite? Heart-shaped sliders. They’re so cute and add such a gorgeous detail. I’m genuinely obsessed and keep buying them over and over again 💕.
Garter Belt Hardware
These are the little clips that hold stockings onto garter belts. They come in plastic or metal and in different colours. Essential if you’re making garter belts (obviously), but also just satisfying to use.
Buckles
I use plastic buckles quite often on swimwear, underwear, and bralettes. They’re easy to work with and super affordable, which is always a bonus when you’re testing out new designs.
Ribbon – The Little Detail That Changes Everything
Alright, before we move on, I need to talk about ribbons because honestly? They’re a game changer. Adding a little ribbon bow to your underwear takes it from “homemade” to “ooh, where did you buy that?” in about two seconds flat 🎀.
What I love about ribbons is how much personality they add. A tiny bow can completely change the vibe of a piece – it can make it playful, elegant, vintage, or modern depending on the colour and style you choose. Plus, ribbons come in such a fantastic selection of colours that you can match them to literally any fabric tone.
Now, here’s the fun part – making ribbon bows is ridiculously easy. We’ve got a video tutorial on YouTube showing you how to make a perfect ribbon bow using a fork in less than one minute. Seriously, it’s that quick!
Here are the ribbon widths I use most often:
1.5cm Ribbon (My Go-To)
This is the ribbon width I mention in the fork bow tutorial. 1.5cm satin ribbon is perfect for creating those cute little bows that sit flat against your underwear. The size is just right – not too big, not too small – and it ties beautifully.
1cm Ribbon (For Flat Bows)
When I want to make a flat bow with a slider in the middle for a more streamlined look, I reach for 1cm ribbon. It creates a lovely delicate effect and works brilliantly when you don’t want too much bulk.
4cm Ribbon (For Special Occasions)
When I’m making something a bit more special or dramatic, I go for 4cm wide ribbon. For these larger bows, I use the same fork technique from the video, but instead of a normal kitchen fork, I use a salad fork (the bigger one). It works exactly the same way, just gives you a bigger, more statement bow.
Pro tip: If you want to try different colours without breaking the bank, ribbon multi-packs are brilliant. You get loads of colours to play with, and you can match them to all your fabric projects.
Honestly, once you start adding ribbon bows to your makes, you won’t want to stop. They’re addictive 💕.
Gusset Fabric – The Unsung Hero
Okay, this probably should’ve been in the fabric section, but it deserves its own shoutout. I use a specific type of polyester for the gusset, and honestly, I’ve tried everything – jersey, cotton, all the things people recommend – and nothing beats this. It’s soft, it doesn’t tear easily, and you don’t even need an overlocker because it doesn’t fray. Game changer.
Tools – Because You Can’t Sew With Your Bare Hands (Trust Me, I Tried 😂)
Let’s talk about the actual tools you need to get the job done:
Scissors
You need proper fabric scissors to cut your fabric cleanly. Don’t use your kitchen scissors and then wonder why your edges look like they’ve been attacked by a angry beaver 😂.
Chalk
Fabric chalk is essential for outlining your pattern pieces on the fabric before you cut.
Rotary Cutter & Healing Mat (Optional But Nice)
Some people swear by a rotary cutter and healing mat. I’ve tried it, and it’s not bad, but I personally prefer scissors – probably just habit. If you do use a rotary cutter, you definitely need the mat so you don’t wreck your table. And if you use the rotary cutter, you don’t need chalk (what a bonus 💪).
Pins
Sewing pins are essential for holding your fabric in place before sewing. Make sure you get decent ones that don’t leave big holes in delicate fabric.
Clips (For Delicate Fabrics)
If you’re working with leather effect or mirrored fabric, pins can leave permanent holes. That’s where fabric clips come in handy. They hold everything in place without damage, and the ones I use come in their own box so you don’t lose them all over your sewing room.
Threads
My top choice is Gutermann thread. It’s strong, high quality, and pretty much every sewing machine accepts it without being fussy. If Gutermann feels too pricey, polyester thread is a solid alternative and still good quality.
Needles (THE Most Important Thing)
Seriously, if you get your needles wrong, your entire project is doomed before it starts. For any stretchable fabric, you MUST use ballpoint needles or size 75/11 needles. These prevent thread looping on the back, stop holes forming in your fabric, and make everything sew smoothly. Don’t skip this.
Rulers
If you like adjusting patterns or cutting out sections, quilting rulers are super helpful. I’ve had mine for about eight years and they’re still going strong.
Sewing Box
A proper storage box for all your tools and supplies will save you SO much time. No more running around the house screaming “where are my scissors?!” at 11pm when you’re mid-project. Everything stays tidy, organised, and in one place. Your sanity will thank you.
Fabric Care – Make Your Creations Last
Alright, you’ve made something gorgeous. Now you need to look after it properly so it doesn’t fall apart after two washes.
Liquid Detergent
I use gentle liquid detergent and ATTITUDE Laundry Washing Liquid to pre-wash my fabric and to wash finished projects. It keeps the texture lovely and stops colours from fading too quickly. These two products are genuinely amazing for keeping your handmade pieces looking fresh.
Washing Bags
If you’re tossing delicate lace into the washing machine without protection, you’re basically asking for it to get shredded. Washing bags protect your delicate fabrics – especially lace – and make your creations last way longer. Honestly, if you want to preserve your hard work, washing bags are non-negotiable.
Bonus: One More Tool You’ll Need
Oh, I almost forgot – a seam ripper! Because let’s be honest, we all make mistakes, and unpicking stitches with scissors is a recipe for disaster (and a lot of swearing).
Ready to Start Your Sewing Journey?
Honestly, I wish I’d had a guide like this when I started. I would’ve saved so much money on dodgy supplies and avoided a LOT of frustration. But now you’ve got this checklist, and you can skip all those expensive mistakes I made 🎉.
If you’re brand new to sewing underwear and want to try your first project without spending a penny, grab my free panty pattern – it’s perfect for beginners and comes with full instructions. And if you prefer video tutorials, I share loads of tips and behind-the-scenes sewing content over on my YouTube channel.
Now get yourself sorted with proper supplies, and go make something amazing. You’ve got this 💪.
You might also like: How to Choose the Best Underwear Sewing Patterns
