The Screen - It doesn't always go right!

My idea for the screen was to use 3mm MDF to create the 180 degree surround screen with 1 1/2 boards joined together lengthways, but sadly it didn't work the way I planned as with movement the joints between the boards showed quite badly.

So, I'm trying a different solution - wall paper.  My thinking here is that by putting wall paper over the cracks this should hide the cracks pretty effectively.

If this doesn't work my only other - and final solution will be to apply another layer of MDF over  the existing, but making sure the joints are staggered - in other words creating a laminate.