Waves/Bands of lighter shade, how to fix? (Mimaki CJV150)

That heat setting seems a bit high from my experience. Normally on a cast vinyl I am closer to 35ish for pre and platen heat and I usually just crank the post heater all the way up.

I normally don't ever use low pinch roller pressure. It can cause the pinch rollers to slip which throws the print feed off. I understand if you have to with this material but if you haven't tried with medium or high yet I would do that.

A lot of the time when you change the resolution from it's default on a certain profile it will print with unpredictable results. If you want to switch resolutions it's usually best to choose a different profile that has that resolution as it's default. Your profile doesn't have to match the brand name so you can choose an Oracal or Arlon profile and it will still work fine. Do a little trial and error with the profiles and see if you can find one that works better.

Sometimes banding like that can be due to a problem with the printer itself. The print feed motor system might be malfunctioning or you might even just have some old clogged dampers causing ink flow issues. I would try fiddling with the settings fist but if nothing seems to work, I would start by changing any maintenance parts that haven't been changed in the last year or more.

 

Probably the source ot the problem is not this but I get the best results with speed/quality when printing on 25° only.