The PNG-8 Format

In fact, there is just one PNG format. PNG-8 and PNG-24 are common export labels. There are also various save modes in Photoshop. We will not delve deep into details, but we will cover the standard features.

PNG-8 has characteristics that are similar to the GIF format. It works well for diagrams, drawings, graphs, and text, as well as for images where there are few colors. It supports a maximum of 256 colors.

The PNG-8 examples in this task, like GIF images, use transparency in which each pixel is either completely transparent or completely opaque. Indexed-color PNG can also store partial transparency for palette entries.

When exporting an image with transparency and a matte, set the matte to the same color as the page background. In Photoshop, choose the “Matte” option when saving the image. Without a matte, the image may have jagged edges. If the background is not uniform (such as if it is a gradient, as in block 3 in the mini-browser), then a PNG-8 image with a matte may show a visible border.

Why use PNG instead of GIF? PNG is an open format that uses lossless compression. It is a useful alternative for static graphics like these.