(1)  Create a new image File> New. Width = 755 and Length = 100.  Change the background color to black #000000.

(2)  Press Shift+Ctrl+N to create a new layer. Set the foreground color to #000000 and the background color to #d9d9d9. Click on the gradient tool it’s usually behind the paint bucket tool. Set the gradient to Reflected Gradient, hold the shift key, and draw a gradient going up. Something like this click here. Your gradient should look like what I have here.

(3)  Press Shift+Ctrl+N to create a new layer. Now click on the Pencil Tool change the brush diameter to 1px. Set the color to black. While holding the shift key draw a horizontal line from left to right. Click here to see my example;  Create a new layer and draw a second line this time change the color to        #d9d9d9. Now you have two lines on the image press your down arrow key to more the second line under the black line. Click here to see my example, this will create a grove in you image.

(4) In this step you just have to repeat step 3 instead of drawing a horizontal line you will need to draw a vertical line. Press Shift+Ctrl+N to create a new layer. Now click on the Pencil Tool and change the brush diameter to 1px. Set the color to black. Hold the shift key and draw a vertical line. Click here to see my example. Now create a new layer and repeat the previous instruction but change the brush color to #d9d9d9. You know how to make the grove, click here to see my example. Now you need to merge the two layers with vertical line. Hold CTRL and click on the vertical line layers. With the two layers selected press CTRL+E now the two layers will become one. All you have to do now is just duplicate (CTRL+J) this layers to create more vertical lines