You can create a signature image by signing a piece of paper and then scanning it and saving the scan to a file.
Your signature image should have an 11:3 aspect ratio. Your signature image will be sized to fit into
a 2-3/4 inch wide by 3/4 inch tall space and placed directly above the signature line on Intuit-supplied checks.
Be sure your signature file is in the correct file format.
If you use QuickBooks user names and passwords, the signature file is stored by user name and company. If you do not have
multiple user names and passwords, the Admin is the implicit user.
To do this task
Open the Print Checks window.
On the Settings tab, click Signature.
In the Signature window, click File.
In the Open Signature File window, enter the drive, directory path,
and file name of your signature image.
Note: QuickBooks copies your signature file to the same location as your company file.
Note: You may select the Print signature image checkbox on the
Settings tab using the Print Checks or Printer Setup (under the File menu) windows.
Once set up, the signature prints on all the checks you print, including paychecks, liability payment checks, standard checks,
and bill payment checks.
Printing your company name and address on checks
Adding your company logo to checks
Setting preferences for checking
Changing check fonts
Learning more about printing checks