Whether you're making a structured tote, a soft pouch, or a quilted backpack, interfacing is what gives your bag the right feel, durability, and professional finish. There are a LOT of options out there, so this guide walks you through how to choose them and how to use them.
Find this downloadable Interfacing document HERE for free.
Grab the Free Printable Interfacing Guide
Want this at your sewing table? Download the free Interfacing Guide PDF here. Print it, pin it up, and you'll never have to guess again.
The Quick Answer: Which Interfacing Should I Use for Bags?
- Soft but structured bags, totes and pouches: foam interfacing, like Sew Hippie Foam, Sew Hippie Fusible Foam, or By Annie Soft & Stable.
- Cotton and lightweight fabrics that need a little body: a woven fusible, like Natalie's Fusible Woven or SF101.
- Quilted, plush bags: fusible fleece (layered over a woven fusible to prevent bubbling).
- Bag bottoms and structured flaps: Decovil Heavy or Pellon 926 Extra-Firm.
- Wallets and flat panels: Decovil Light or Pellon 808 Craft Fuse, or layer the fusible woven interfacing.
Keep reading for the details on each one, plus my tips for applying them.
Fusible Interfacings
Fusible interfacing has adhesive on one side and bonds to your fabric with heat. It's fast and easy, and it's great for structured bags and exterior panels.
| Product | Type | Weight | Best uses | Natalie's notes |
|---|---|---|---|---|
| Natalie's Fusible Woven | Woven | Light to medium | Stabilizing cotton and lightweight fabrics, some cork, and soft vinyl | Fuse with a dry iron or heat press, starting from the middle and pushing outward. |
| Pellon SF101 Shape-Flex | Woven | Light to medium | Stabilizing cotton and lightweight fabrics, some cork, and soft vinyl | I've had some issues with the fuse sticking. Fuse with a dry iron or heat press, middle outward. |
| Pellon 808 Craft-Fuse | Non-woven | Firmer | Flat panels and wallets, no curves | Tends to lift or bubble if it's not fused properly. Dry iron or heat press. |
| Pellon 987F Fusible Fleece | 100% low-loft polyester | Light and soft | Quilted bags that need plush structure, when foam isn't recommended, or for beginner sewists | Can "bubble" through thinner cottons. Fuse a layer of woven fusible first, then the fleece on top. |
| Sew Hippie Fusible Foam | Fusible foam | Lightweight with loft, soft with structure | Bags, totes, duffles, crafts | Can be sewn into the seams or trimmed out of them. |
Heavy Fusible Stabilizers (Decovil)
When you want real shape without puffiness, these leather-like stabilizers are the answer.
| Product | Type | Feel | Best uses | Natalie's notes |
|---|---|---|---|---|
| Decovil Light (Vlieseline) | Leather-like non-woven, one-sided fusible | Like heavy cardstock, but flexible | Adds professional structure and shape to bags, wallets, hats, and home decor without loft | The manufacturer suggests a pressing sheet and a mist of water. I've always applied it dry. |
| Decovil Heavy | Rigid non-woven, one-sided fusible | Much stiffer than Decovil Light | Bag bottoms and structured flaps | Firm and sturdy, but still flexible, with a leather-like handle. |
Sew-In (Non-Fusible) Interfacings
Sew-in interfacing is stitched in place instead of ironed on. It's great when you want loft, or when your fabric can't take an iron.
| Product | Type | Weight | Best uses | Natalie's notes |
|---|---|---|---|---|
| Sew Hippie Foam Interfacing | Non-woven foam | Light | Structured bags and pouches, totes | Thinner than Soft & Stable, so it's easier to sew into your seams. |
| By Annie Soft & Stable | Non-woven foam | Light | Structured bags and pouches, totes | Trim it out of the seams for an easier sew. |
| Pellon 926 Extra-Firm | Non-woven | Very firm and dense | Heavy bag bottoms, base inserts, gussets, and sides | Trim out of the seam allowance. |
| Pellon 973 Fleece | Lofty, needled non-woven | Lightweight, thick | Quilted bags and cushioned e-reader sleeves | Use sew-in for better loft. I sew it into the seams, since it can shift. |
Fusible vs. Sew-In: Which Should You Use?
Fusible interfacing is quick, stays put, and is perfect for exterior panels and structured bags. Sew-in is better for delicate fabrics that can't handle heat, for keeping maximum loft (like fleece in a quilted bag), or when you want a softer drape. Both have their place, and lots of my bags use both: a woven fusible on the fabric, plus sew-in foam behind it.
How to Apply Fusible Interfacing (Without Bubbles!)
- Always test on a scrap first. Every fabric and iron is a little different.
- Use a pressing cloth or a Teflon pressing sheet to prevent scorching.
- Start in the center and push outward. If you see an air bubble or wrinkle, gently lift the fabric and re-fuse.
- Heat presses are great time savers. Experiment to find the right settings. I typically use high heat on both my iron and my press.
- Planning to wash your bag? Manufacturers recommend pre-shrinking interfacing by washing it first. (Honestly, I don't, but it's recommended.)
- If your machine hollers about the layers, trim the interfacing out of your seam allowances.
Tips for Sewing with Foam Interfacing
- Machine struggling? Use a walking foot or a longer stitch length. You can also whack the seams down with a nylon mallet. It helps a lot!
- Cut foam larger than your fabric pieces, baste, then trim to size or trim it away from the seam allowance. This prevents shrinkage, especially if you're quilting your pieces.
- Steam out creases before you sew, and store foam rolled if you can.
- Don't toss your scraps! Join them together with my Franken-foam tutorial and save money.
- Foam has memory. Bags pop back into shape even after being squished in storage or travel.
Interfacing FAQ
Can you fuse interfacing to vinyl?
Yes, you can! Woven fusible works on soft vinyl. Use a pressing sheet and test on a scrap first. Watch my tutorial on fusing interfacing to vinyl here.
Do I need interfacing for cork or vinyl bags?
Not always. Some cork does well with a woven fusible, but several of my patterns, like the Donovan Bag and the Frida Bag, need no interfacing with the recommended materials. Always check your pattern.
Why is my fusible fleece bubbling?
Fusible fleece can bubble through thinner cottons. Fuse a layer of woven fusible to your fabric first, then fuse the fleece on top of that.
Is foam interfacing washable?
Yes. Foam is polyester. I always wash on cold and dry on cool.
Should I sew foam into the seams or trim it out?
It depends on the foam and your machine. Thinner foams like Sew Hippie Foam can be sewn into the seams. Thicker foams like Soft & Stable are easier if you trim them out.
What's the difference between Sew Hippie Foam and Soft & Stable?
Both are sew-in foams for structured bags. Sew Hippie Foam is thinner, so it's easier to sew into seams. Soft & Stable is a bit thicker, so I trim it out of the seam allowance.
Shop the Interfacings I Use
Everything I use and recommend is in one place: shop the Interfacing collection, with woven fusible, foam, fusible fleece, batting tape, and more.
Questions? Email us at help@sewhungryhippie.sbs or call 888-351-3869 and leave a message. For more tutorials, visit my YouTube channel, and I hope you'll subscribe!
At the end of the day, trial and error will always be your best teacher. Don't be afraid to mess up. It's part of the process!
Peace, Love, Sewing,
-Natalie
