Yes.  You would save the signature as a image file and then customize the check to add the image to it.  We have detailed steps on the process in this article from our public knowledgebase: https://support.na.sage.com/selfservice/viewdocument.do?noCount=true&externalId=16285

The process works on AP and Payroll checks, and can also be used to add a logo to a check.