The Problem: Most people design for their laptop screen, but digital signage often lives on vertical "totem" displays or unique menu boards. If you stretch a standard slide, your content ends up distorted or boxed in by awkward black bars.
The Fix
PowerPoint is more flexible than you think. Before you add a single text box, you need to set your "Canvas." Navigate to the Design tab, click Slide Size, and select Custom Slide Size.
For Portrait Screens: Click Portrait to switch to portrait setup.
Pro Tip: In a vertical layout, the human eye naturally scans from top to bottom. Place your most critical information—like a headline or a QR code—at eye level (usually the upper-middle third of the screen).