Check your press temp, pressure and dwell time
We like the 3M 5807 a lot, and I am personally a 3M "hater" lol.Thanks for all the help and advice everyone!
I normally use the 3M™ Scotchlite™ 5807 Heat Transfer Vinyl from Stahls - I find it is much easier to cut and weed, as well as apply compared to the Joto reflective materials. I'll definitely stick with using this in the future.
Till my next problem.