Use a simple technique to design a piece of the realistic rope by this example. There are many step that will help you about this effect so follow this example.
New File: Take a new file, set the foreground and background color as given below.
Effect: Go to Filter Menu > Sketch > Halftone Pattern and use settings.
Make Similar Background: Hold Alt key and scroll your mouse, a new same background will come then press Ctr + T and turn as given below.
Selection: Selection Rectangular marquee tool (M key) and make a selection then copy it.
Past Selection: Take a new file with same size of the selection then paste.
Change color: Change foreground and background color as given below.
Fill Color: Go to Edit Menu > Fill as given below.
You will get it.
Effects: Go to Layer Menu > Layer Style > Bevel and Emboss, Inner Shadow use same settings.
The final result is here.
Recommend the tutorial