This week I wanted to talk about pacing the voiceover in a video. I was thinking about this after I was asked to write a script for a video lasting one minute and 20 seconds, based on a 900 word press release. There was nothing wrong with the video, and nothing wrong with the press release, but the company in question was struggling to marry the two together.

It took me three minutes to read through the press release, so clearly that wasn't going to fit. But scripting for video is more than just doing a basic editing job. You have to get into a whole different mindset and a whole new way of working.

If you consult BBC guidelines for narration, then you'll find that it's specified at about 140 words per minute. For more complex concepts, or where you want to be a bit more deliberate about what you're discussing, I'd suggest around 120 words per minute. If you were trying to be very sales-oriented or deliberately generate excitement, then you might push as high as 170 words per minute. But for the video I was looking at, 120 words per minute felt about right.

That immediately constrained the length of text I could produced for the script, but I also had to look at the way the different shots fell - the length of time on any given scene. You want your dialogue to relate directly to what the viewer is seeing, not to be either ahead of it or behind it. That again impacts on the pacing and content of your script.

It's very important to take your script and read it out loud to yourself while the video is running - not just to make sure it fits the video, but also to look at aspects such as where you're going to breath, and how natural the sentences feel. Remember that you're writing for the ear, not the eye, so it's perfectly acceptable to use contractions and a more conversational style.

The more accurate the timing of the copy, and the more it's written for the ear, the easier it will be for your voice talent to effectively communicate the message. What that means at the end of the process is that more people will watch your video all the way to the end – which, after all, is what we're all trying to achieve.

As an aside, I charged £40 to write that script. That might sound quite a lot for 151 words, but think about how much time it saved. And I'd like to think that the finished video will be much better for it.