Have you taken out the plastic piece from the center covering the battery? That keeps the light leaks from doing their job. Just tape yer battery in place!!! I made the mistake of not doing that and got 12 shots of a battery.
I will be shooting the Holga with the mask in place. I like the 6X4.5 format. The first photo is of someone checking the VIN plate for the make of the Futuramic. Turned out to be an Oldsmobile.
Well that makes sense then! I kinda liked the format with the mask in too, but I like the vignetting too much. Plus I destroyed my mask by trying to alter it... so I can't go back now...