Home » Tip of The Day » Straight Lines with BrushesStraight Lines with Brushes March 16, 2016. Posted in: Tip Of The Day. To paint a straight line with any of the brush tools, just click on the canvas where you want to start your line, then hold the Shift key, and click where you want the line to end. Photoshop will then paint a straight line between these points. « Previous Photoshop Tip: | Next Photoshop Tip: » Sign-up for the PTC Newsletter so that you'll never miss a tutorial!. Your Email Address: