In general you won't see Black Background Design covered in text books or classes. It's not something I've ever had covered in any multi-media class but it has been a worthwhile trick that I've had up my sleeve for quite a while.
So what is Black Background Design?
Before we dive into what it is, we first need to understand several ideas. The first being that when the colour black is projected on to a surface (wall, projection screen etc.) there is no light being projected. The second is that when you have a black background your audience can't tell where the projection ends and starts. The saying "ignorance is bliss" is essentially what we are taking advantage of. In other words what your audience doesn't know can be taken advantage of in how you make design choices. In order for this to work the surface you're projecting on must be bigger than the amount of space the projection takes up.
So then what is Black Background Design?
Black Background Design takes advantage of all the space on the slide. This is possible because your audience can't tell where the slide starts and ends. This means that the space you place between the edge of the slide and any text, images, shapes and lines doesn't need to be there ( this space is often referred to as "White Space").
Let's look at some world examples:
I have text to display but I also want to show some images next to it. If I use a white background then I need to leave space between the outside of the slide and the content to avoid the slide looking overcrowded. Now with a black background the audience doesn't know where the edge of the projected image is. Therefore, you can increase the size of the text and images because White Space is no longer a problem. This is particularly helpful if you want to increase the size of things being projected without moving the projector backwards to increase the image size.
If you look at the photo below you will see an example of a black slide (left), a white slide with some white spacing (centre) and white slide with no white space (right). Notice how the one on the right looks over overcrowded, whereas the one on the left doesn't.
Photo: Note that all the photo I use have been effected by white balancing issues and thus look like they were taken in a dark room. This does not mean that Black Background design only work in dark environments as it also works perfectly in well-lit environments.
Another trick you can do is to move the content around on your screen. Let's say I'm at a school presentation night. They might have the national anthem, awards and some of the staff members might have a speech. For the national anthem I'll use the top half of the screen. For the awards I'll use top/middle. And for the principal's address I'll just use the middle of a slide (keeping in mind that each item is on its own slide).
An adaptation of this is to expand the content down the slide depending on how much you have to display at once. An example of this would be to have the first verse of the National Anthem take up the majority of the slide. Then have the principal's address take up just the top half until he wants to show an image of something. And then the awards slide just take up the top of the screen.
In both these ways you keep your audience guessing how tall the projection is.
Situations where Black Background Design doesn't work:
If you wanted to have an image as a background you effectively show the edge of the projected image thus giving away the edges. To avoid destroying the effect completely you could erase the outside of the background image with the soft version of the erase tool in an image editing software. This way the edge of the projection is still hidden. Alternatively you could use some line art – don't place it too high if you have text or an image very close to the top of the slide because you want to keep the allusion that something could be projected above.
If you have a projection screen that is filled by the image projected this trick won't work as the audience can see the edge of possible projection space. Placing items closer to the edges of your slides in this case will still make you slides look overcrowded as there is no possible perceivable space around the projected image. There is no way to get around this unfortunately.
Black Background Design can be a worthwhile trick with a powerful impact when used correctly.
Zach Radloff lives on the Gold Coast and is studying IT and Multimedia at university and is also a qualified Live Production, Theatre and Events Technician.
Zach Radloff's previous articles may be viewed at www.pressserviceinternational.org/zach-radloff.html