An illustration that looks crisp on your screen turns grainy on the projector; artwork ends up sitting under the text. Slides have their own constraints, and they are easy to get wrong.
Know how big a slide actually is
PowerPoint and Google Slides default to 16:9 widescreen, which is about 1280 × 720 pixels. Older decks and some meeting-room projectors still use 4:3, about 1024 × 768.
So even a full-bleed background only needs around 1280 pixels. Photo-editing-sized files are unnecessary.
How much resolution you need
A useful rule is one to two times the width you intend to display. Half the slide width means roughly 700 pixels; full bleed means roughly 1300.
Double that if the deck will be printed and handed out. What looks fine on screen shows its grain on paper. For print, aim for 2000 pixels or more at full bleed.
Do not stretch
Blowing up a small image softens every edge. If the image lands smaller than you wanted, look for a larger original rather than scaling it up.
Do not change the aspect ratio either — people and objects distort in ways viewers notice. Drag a corner handle to keep the proportions; the handles on the middle of each edge will not.
Placing text over artwork
When text sits on an illustration, put it where the artwork carries the least detail — a near-flat area, or the empty space a composition leaves open.
Where an overlap is unavoidable, lay a semi-transparent band behind the text, or fade the whole illustration back before adding type. Outlining the text also works, but a deck full of outlined text starts to look busy.
One image per slide
A slide should be readable in a few seconds. Several illustrations split the viewer’s attention away from what you are saying. Start with one per slide and add more only when the content demands it.
Consistency helps too. Line art next to realistic 3D reads as a patchwork. Keeping one visual register across the deck is most of what makes it look considered.
Watch the file size
A deck full of high-resolution images gets too heavy to email or share. PowerPoint can compress images in place; running it once before you distribute the file costs almost nothing in visible quality.
About Visual Hub assets
Our assets come as squares (1024 × 1024) and landscape (1408 × 768). Landscape suits full-bleed slide backgrounds; squares sit well beside body text. No credit line is required, and both internal and client-facing decks are fine.