Raster format is also known as bitmap or BMP. They mean the same thing and are comprised of pixels, so when you enlarge them they become diluted. It's the most widely used clipart format and is usually all you need.
When scanning a drawing into your computer it will always load as a bitmap image, (a bit like a photograph in a newspaper). This can be sent directly to a stamp manufacturer as long as it is a black and white scan and the line thicknesses do not fall below the minimum. If the lines are too thin you can convert the bitmap image into vector data by applying a trace to the image. Programs that have tracing ability place a vector line around the lines or can be set to follow the lines, these lines can then have a thickness applied to make them suitable for rubber stamp making.
Christmas day is magical, but we often forget what makes it so great. All month long you have been getting invitations and fliers to parties, dinners, and gift exchanges in your neighborhood. What did all of these fliers look like? Were they plain white paper with size 12 font, Times New Roman? No, of course not! They were exciting with unique fonts and loaded with Christmas clipart! These Santa graphics spice up the holiday season like you can't believe!