I have then sent back and had to wait for a new one while.
The new had then also 'spots' but only on the side rather faded markings from 'Schneider'.
This should, however, go in the wash out.
What still bothers me is that the screen is really very thin and thus everything shines through behind it and it bends easily. To iron the screen with its 3x3m thus presents itself as a challenge.
And since you still need to buy to the stands (which also again good 40 cost) holding 31 I (with delivery expected to) for a lot of money for the quality.