Top Tips for Creating Posters Using Power Point
In PowerPoint, don't put elements with Transparency on top of other elements with Transparency. This produces VERY unpredictable results. Some templates have transparent elements. Avoid these.
Picture backgrounds should be inserted using "Insert, Picture, From File" and not via the "Format Background" command. Using "Format Background" produces backgrounds that print very pixelated.
Most background colours are OK. But please don't make it solid black.
Bring a PDF as a backup
Some Powerpoint files simply don't print or have elements that change position, or size, or font. Use the "File, Save as PDF" feature to make a backup PDF and bring it along.