You will need
To create a layer in the open Photoshop document straight line, enable the Line tool by clicking on the icon in the tools palette or by pressing U. Click on the part of the image from which the line should begin and hold the left mouse button, drag the segment to the desired length. If you need to get a direct horizontal line with the help of this tool, hold down the Shift key while drawing.
The thickness of the line created with the help of Line Tool, you can configure in the panel that appears under the main menu after switching on the instrument. To configure, enter the desired size in pixels in the field Weight.
Line drawn with Line Tool in Shape layers mode, will be located on a new layer with a vector mask. Mode Paths this tool to create a vector image, and in the mode to Fill pixels you will get a raster linelocated on the active layer. In the left pane of the settings Line Tool to switch modes, which works by clicking on the appropriate button.
A straight line you can create using the Pen Tool. Place two anchor points using this tool, by clicking them on the open document. The points will be connected by a straight line. To obtain a straight horizontal line before creating the second node point, hold down the Shift key.
Lines drawn with the Pen Tool, stroke with a brush. To do this, select Brush Tool and adjust the diameter of the brush panel, Brush or palette Brushes. The brush diameter will correspond to the thickness of the line.
In the Paths palette click on the layer with the line right click and select Stroke Path. Select the Brush tool in the dialog box. If you need line, beginning and end which will be thinner than the middle, put a tick in the check box Simulate Pressure.
To create straight even lines you can use the Brush Tool and Pen Tool. If you hold down the Shift key while drawing your line, leave tool. In the same way can be made to move in a straight line tools designed to lighten, darken, erase, and copy image. The thickness of these lines will depend on the diameter of the selected brush tool.