Straight 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: » Get The Tip of The Day in Your Inbox! Sign-up for the PTC Newsletter to receive a weekly re-cap of the Tips of The Day. That way you'll never miss a tip. You'll also get instant access to the Subscriber Only Tutorials! Enter your email below to sign up! Your Email Address: You Can Also Get Daily Tips On Your Feed! Every Photoshop Tip of The Day is posted in our Facebook & Google Plus, Twitter, LinkedIn, and Pinterest pages.