Review on Heat Transfer Vinyl Bundle: JANDJPACKAGING Sewing Essential for Easy Apparel Customization by Karla Richter

I've used it on cotton bags before and had no problems. However for the past few days I've been trying to make a jumpsuit for my new niece and nephew and no matter what I do I can't get this vinyl to stick to the cotton/poly blend. It's simple and I like the color variety, but right now I'm just frustrated because it's the majority of my HTV because of the color choice and I feel like it's useless. I tried the instructions that came with the vinyl and it wasn't enough. But if I heat it longer or use a higher temperature (I've tried both) then the backing film will stick with my light pressure and ruin the design, lift part of the letter but not the whole, or wrinkle the design.