Raster (bitmap) images are made of pixels (tiny square dots) with different colors and tones to produce an image. These images are created by digital cameras, scanning images, or raster-based programs such as Photoshop and Corel Painter. Each image file contains a set number of pixels, and the number of pixels determines the quality of the image, which is known as resolution. For printing, we recommend the dimensions of the image to be at a 1:1 ratio with a resolution of 300 dpi (dots per inch).

Vector images are formed by mathematical calculations of lines and curves that connect the anchor points, which keeps the lines sharp. Since vector images are not pixel-based, they can scale up or down without losing quality or detail. These images are created using vector-based programs such as Illustrator and CorelDraw. They can also be created from raster-based programs that support “vector path drawing,” but this process is more advanced and requires the designer to export the file correctly. For printing, we require vector files for foil, spot UV, debossing/embossing, screen printing, etc

 When to use Raster or Vector

Photographs, images, or scanned documents for your book content and cover should be created as raster graphics of good quality (300 dpi at a 1:1 ratio). Tables, charts, and shapes should be created in vector format. Cover finish files, such as foil, spot UV, embossing, and debossing, MUST be done in vector format.

For logos, illustrations, or any graphics that require clean, scalable lines, vector images are the best choice. Vector images ensure that the graphics remain sharp and clear at any size, which is crucial for branding materials, large-format prints, and intricate designs involving foil, spot UV, debossing/embossing, and screen printing.