It’s important for copy to be accurate, but it’s every bit as important for the visuals that accompany the copy to be equally accurate. Visuals either lend credibility to the messages being presented, or they detract from it. That’s especially true when they’re related to some kind of technical message.

I saw proof of this when an ad agency I worked for was preparing a major presentation to a new air cargo company client. One element of the presentation was a paint scheme for the company’s airplanes, and the art director assigned to the task had come up with a beauty. The only problem was that his drawing applied the design to a plane that didn’t exist. He had created the outline of it using a nose from this plane, a tail from that one, engines from a third, and so forth.

I warned the boss that the client wasn’t going to react well. “These are airplane guys,” I said, “And showing them a plane that doesn’t exist will say that we don’t know what we’re doing. This stuff matters to them.” I urged the team to create a new rendering using the Boeing 727 model the company would be flying, but my concern was brushed off as paranoid.

When the team returned from the presentation, they were glum. They had hoped to dazzle the client staff by opening with the design, but instead received an extremely negative response. The clients were confused, because the plane looked nothing like theirs (nor anything in the air), and they treated the team like fools for bringing it to them. That misstep put a damper on the entire presentation. The boss looked at me and said, “You were right.” I wasn’t looking for vindication, though. I would have preferred that the presentation be the huge hit it was supposed to be.

I ran into a similar situation when a real estate client developed a presentation piece for a major presentation to logistics decision-makers. They had asked the designer to add a photo of a train, and not knowing anything about railroading, he used a stock photo of a British locomotive. Most people wouldn’t know the difference, but this important audience would. They knew which railroads crossed this part of the country and knew exactly what type of locomotives and cars they used. Had the client gone ahead with the original photo, that photo would have undermined their claim that they really understood American logistics.

It’s easy to grab a stock photo that looks right to you. It’s a lot tougher to develop an understanding of what’s important to your audience. But only one of those approaches will make you look like you really know what you’re talking about.