Keeping flies out of PVC conservatory...

[Dontloookbackinanger]

Our house has a small white PVC conservatory. We live in the countryside with flies aplenty and at least half the population find their way into the conservatory by the end of the day. They seem to be attracted by the bright white plastic. The next day there are dead flies carpeting the floor.
I have fly papers but if anyone has any tips for stopping them getting in there in the first place (other than sealing the door) I would love to hear them.

You can get those mesh screens that fix to the door frame and have magnets along the centre seams so you can just walk through and the edges snack back shut behind you. Don't know how well they work, but worth a try for about a tenner? JML Snap Screen.