Home » Tip of The Day » The Line ToolThe Line Tool October 29, 2015. Posted in: Tip Of The Day. When using the Line tool, use the bracket keys ( [ or ] ) to decreases or increases the line width by one pixel. Adding the Shift key will increase or decrease the line width in increments of 10 pixels. « Previous Photoshop Tip: | Next Photoshop Tip: » Sign-up for the PTC Newsletter so that you'll never miss a tutorial!. Your Email Address: