A comment
I have not had a greenhouse for the first year. And until recently, each time in the spring I was confronted with the painful question of what kind of coating film to buy, so as not to run into an expensive, but ordinary film, the whole advantage of which is the simple lies of marketers. Three years ago I decided to try reinforced film. I shot it for the winter, because I saw an example of a neighbor who left her, hoping for strength. The film actually withstood, but the wooden frame of the greenhouse is not.
As for the light transmittance, then, first, the seedlings, and then the tomatoes in it grow beautifully.
I use film No. 17 of the Plastic plant, 170 microns thick. I think it is impractical to take thicker with reinforcement, since it is still necessary to change after 3-4 years, even if the coating itself is intact. From microdamages, the light transmittance greatly decreases.
pros
It turns out cheaper than buying a new one every year.
Minuses
For the winter, you still need to shoot.