Embossing is the raising of one section of a design above the rest, causing that area of the cover to stick out. Debossing is the lowering of one section of a design below the rest, creating a sunken-in look and feel. This feature adds texture and depth to projects and is often used in combination with other specialty options such as foil stamping.
For this effect, a custom die is created. The die is installed into a deboss/emboss machine, and markers are set up to ensure alignment. Once the markers are added the operator runs the press and the die is pressed into your project. The high pressure and heat cause the material to drop around or in the shape of the die – your design.
When it comes to hardcovers, debossing is used to create both effects. For example, if you wanted your title to be debossed, the machine would apply the pressure in the shape of your title. If you wanted your title to be embossed, the machine would place pressure everywhere except your title, effectively debossing everything that isn’t supposed to be embossed.
Watch the process of embossing a book’s title