We have printed several large posters that have been made in Powerpoint. The
finished posters are usually about 4ft x 3ft, and we save them as either ppt,
pptx or pdf files.

Unfortunately, several of our posters are marred by big crosses through the
text boxes and/or images. We can't figure out why - it doesn't happen when
they are printed on regular-sized paper, just on poster-sized paper.

(Sounds like an issue with the printer?)

Any suggestions would be greatly appreciated.

Thanks!