If you love to make shirts with your Cricut machine you are going to love the new SportFlex Iron On™ Vinyl! It has enough stretch that is perfect for work out shirts, swimsuits, workout gear, yoga pants, leggings and my favorite..maternity shirts! I am going to show you exactly how to use Cricut SportFlex Iron On™.

It’s no secret I love to make shirts with my Cricut. I especially love to make funny baby onesies and maternity shirts! The dilemma I encounter with the maternity shirts is that the shirt obviously stretches over a belly (and even the girls!)…normal heat transfer vinyl does not. This is where the new Cricut SportFlex Iron On™ is is a match made in stretchy heaven!

Here is a shirt I made for myself when I was pregnant with Spangenbaby. (Please don’t mind the awkward belly selfie) Do you see the poor iron on hanging on for dear life as the shirt stretches across my belly? I know, I feel sad for it too!

Here is the shirt I made with SportFlex Iron On™! (No, not my belly but a friend’s — this baby shop is CLOSED!) See how much better that works? It’s thin, super flexible and has stretch to it and is perfect for Nylon and Polyester materials like work-out clothes!

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Supplies Needed for Cricut SportFlex Iron On™ Project:
- Cricut Cutting Machine
- SportFlex Iron On™ in your choice of color(s)
- Scissors
- Weeding Tool
- Blank Maternity T-Shirt
- Cricut EasyPress™ or Iron
- EasyPress™ Mat
- Thin Cloth (optional)
You can find many of these items in my Shop on Amazon!

I made this fun file using the font Arab Brushstroke std Regular from Cricut Access as well as a circle shape! Nothing fancy and you can find the Cricut Design Space file here.

How to Cut SportFlex Iron On™:
- Load your mat with the SportFlex Iron On™ lining side down.
- For the Explore Family turn the Smart Set Dial to Custom. Select SportFlex Iron On™ from the list of materials. For the Maker select the SportFlex Iron On™ Setting.
- MIRROR your design.
- Cut your SportFlex Iron On™

How to Apply SportFlex Iron On™:
Using an Iron:
- Using the Hook tool, weed your design. This means removing the extra iron-on material from the lining sheet leaving only your intended design.
- Set Iron to WOOL setting. Make sure the steam to the iron is OFF.
- Use the iron to preheat the area you will be applying your design. Preheat for 5-10 seconds.
- Apply the SportFlex Iron On™ onto your blank with the lining UP. You do not need to use a thin cloth, however, I recommend it so that you don’t get Iron imprints on your shirt! The thin cloth really helps!
- Apply Medium Pressure and press for about 20-30 seconds.
- Flip the material over and Iron on the backside for about 10 seconds.
- Let cool for 1-2 minutes and remove the plastic lining. (This is called a Cool Peel)
Using a Cricut EasyPress™ with EasyPress™ Mat:
- Set Temperature to 305 F/151 C.
- Preheat the area for 5 seconds
- Apply the SportFlex Iron On™ onto your blank with the lining UP. For Polyester fabrics, use a Teflon Sheet or piece of parchment paper. This is not necessary for Nylon materials.
- Press for 30 seconds.
- Flip the material over and Press backside for about 15 seconds
- You may then remove the plastic lining (Warm Peel)

If using Cricut EasyPress™ with a towel in place of the EasyPress™ Mat:
- Same as above except use 315 F/157 C temperature settings.
Tips for Using SportFlex Iron On™
- It is recommended to ONLY layer with other colors of SportFlex Iron On™ and only 2 layers at most.
- Wait 24 hours to wash.
- Wash and Dry with the garment inside out.
- If you need to re-iron your garment, do so from the backside of the fabric.
- Make sure to follow my Preparing your Blank instructions before applying your SportFlex Iron On™
This is not just for maternity shirts, it also works great for swimsuits, leotards, Dri-fit workout gear, leggings and more! Perfect for all those Nylon and Polyester shirts you couldn’t personalize before! Order as an 11.8 x 24 sheet, which can make multiple projects depending on size and it also comes with the Cricut StrongBond™ Guarantee.


You might also find these Cricut posts helpful:
- Getting Started with Your Cricut
- Heat Transfer Vinyl Basics
- Cutting Heat Transfer Vinyl with your Cricut
- How to Upload SVG Files into Cricut Design Space
You might also really like these Cricut projects:
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Comments & Reviews
Jodi Geers says
I have a question….what is your opinion about using the Flex Iron-on on %100 Cotton? Will it still work even though the material doesn’t give like polyester or knit? Thank you for your help!! The tutorial is really helpful. I’m such a newbie.
Cheryl Spangenberg says
It will still work Jodi but you could probably just get away with using the regular Iron-On or Iron-on Lite in that situation! Since it doesn’t need the stretch!
Lanie says
I just tried sport flex for the first time. It looks wrinkly when it cools. Not crisp. But I thought it would be lighter on a shirt, not the heavy plastic feel that regular vinyl has. What did I do wrong.
Cheryl Spangenberg says
Hi Lanie! Some questions first: 1. Did you prewash your shirt? 2. What kind of shirt were you using? What fabric? 3. What heat settings did you use and was it with an EasyPress or an Iron? I haven’t had this problem so I am hoping we can figure it out.
Laura says
Thank you so much for this tutorial! I struggled so badly until I came across this post! God bless you!
Cheryl Spangenberg says
So happy to have helped, Laura!
Jess says
How do you measure for vinyl placement on bump shirts? How many inches down does the design start. Is there any good guides for this?
Cheryl Spangenberg says
Hi Jess, that is a great question. If the shirt has rouching on the sides I normally center within that if not, I’d just try it on if you can, and mark the area. I am not sure there is a rule of thumb you can follow since all maternity shirts are so different.