See The Brush Size On The Magnetic Lasso Tool May 15, 2016. Posted in: Tip Of The Day. When using the Magnetic Lasso tool, press the Caps Lock key to change the cursor to the brush-size indicator. This lets you see more precisely the area that the tool is selecting from. You can use the Bracket keys ( [ or ] ) to change its size. « 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.