See below for 2 quick troubleshooting tips if you notice an unwanted white border along the edges of your prints.
First, confirm that your border settings within Social Booth are correct. You'll find these setting options under the Printer tab in Social Booth:
If these settings are correct, and you are still having a border issue, be sure that the Border feature within your Printer Settings is not selected.
To get to the settings area of your printer go to your tablet's Devices & Printers. Next, right click on your printer and select Properties. Under the Options tab you will notice the Border feature. Be sure it is not selected. See below for a few images to reference!