Despite its name, Photoshop CC's Line Tool isn't the only option for drawing a line. In many situations, it's not even the best tool for the job. The Line Tool can create dotted lines and arrows, but if you're just trying to draw a clean straight line, or want to draw using various brush styles, you'll have an easier time with the Brush Tool instead. To draw curved lines, learn to use the tricky Pen Tool.
To draw straight lines, select the Brush Tool and hold the Shift key while you draw to lock the line straight. To draw multiple line segments, hold Shift and click once to place the end of each segment, drawing the line in between. These methods work in conjunction with other Brush Tool settings: Pick a preset brush style or set the size, hardness, shape, opacity and other brush options on the top toolbar to draw different types of lines.
Line Tool Basics
Right-click the Rectangle Tool icon and choose Line Tool. Click and drag to draw a line. Holding Shift with the Line Tool locks the line to a 45- or 90-degree angle.
The top toolbar for the Line Tool has several options, many of which don't behave as you might expect at first glace. To change the thickness of the line, adjust the Weight setting. Set both the Fill and Stroke colors to the same color to create a solid line. If you turn off the Fill color, you end up with a hollow line. It helps to remember that the Line Tool is an offshoot of the Rectangle Tool; lines are simply narrow rectangles, not single strokes as with the Brush Tool.
Advanced Line Options
Click the Stroke Options icon to change from a solid line to a dashed or dotted line. These options also include Align, Caps and Corners options to customize the style of the line and its endpoints. The stroke options apply only to the Stroke part of the line, not its Fill. If you have both the Stroke and Fill colors set the same, you won't see any dots or dashes, thanks to the Fill color filling in the gaps. Set the Fill color to No Color or an alternate color to avoid this problem.
For more control over the dash style, click More Options. Set the Dash and Gap values to customize the length of the dashes and gaps in the line.
Select the Pen Tool to draw lines and curves using . The Pen Tool takes getting used to, but is the best tool for creating complex shapes.
Draw Straight Lines
Click to place the ends of each line segment with the Pen Tool, and Photoshop draws the line in between. With single clicks, the Pen Tool always draws in straight lines, but holding the Shift key locks the lines to 45- and 90-degree angles, creating cleaner shapes.
Draw Curved Lines
After you click to place the end of a line segment with the Pen Tool, continue holding the mouse button and drag to adjust the curve of the line. As you draw the shape, you'll see straight lines tangential to the curve that help indicate how you've positioned each curve. These lines are hidden after you finish drawing and deselect the shape.