Im putting mylar in my grow room but im going crazy trying to keep it perfectly flat and clean. Is it a big deal if its not perfectly smooth and if there is a few smudges from my finger prints?
I agree it doesn't need to be perfectly smooth and a few random fingerprints and such won't have an impact, but your post title is about "wrinkles", which definitely will reflect the light off at odd angles. Get it as smooth as you can but don't obsess over it.