I am not really sure how to explain what happened, but I thought the occurrence was interesting enough to warrant an article. I had taken a photograph of two old doors. Below is what the the photograph looked like on the monitor.

If you look particularly in the areas of shadows, you will probably assume that even the areas of intense shadow are a shade of white or light gray. However, when I printed the image, the areas of shadow were a similar color to the color of the swatch below.

The printer I was using was an Epson Stylus PHOTO R2400. I tried different color profiles and different papers, but the color of the shadows varied only a small amount. After making two 13" x 19" pictures and a number of smaller ones, I decided that the printer must be malfunctioning. I then tried to print two other scenes. They printed perfectly. Now I really was wondering what to do.

The color of the swatch certainly did not resemble the color in the area designated by the black line. Next I scanned in the print on another machine and looked at the image. It appeared to have the same characteristics as the original.

Still puzzled as to what to do, I used the magic wand to separate the most densely shadowed area from the rest of the image and then did a copy and paste to form an new image.

The color of the shadows matched the swatch. When I looked at the main image after using the magic wand, I noticed the shadow area appeared darker when it was separated from the rest of the image by use of the magic wand.

When I put the original image next to the one (the image immediately above) on which I had used the magic wand to separate the shadows, I could see the difference.

When I tried this experiment by scanning in the printed image and working from it on a different machine and monitor, the results were exactly the same. That is why I call this piece my "Optical Illusion". I could also call it my expensive piece since I wasted a lot of paper and ink on it.

• As always, I invite you to visit my web site, Perpetual Visions

• The Paula Sanders Report is a regular Renderosity Front Page featured column, where Paula investigates and comments on graphic software, techniques, and other relevant material through her reviews, tutorials, and general articles.