I am so happy to be able to answer this because I just learned it and did it myself.

You use an impressioin matt (earlenes 1 inch or 1 1/2 inch diamond matt) imprint the cake then use a tool (i have the wilton fondant tool that has three attachments) and you run the tool over the lines to create the quilt ldotted look. I researched online until I found out how to do it and it worked wonderful.
