I will be using my 10x14 CCS 1.1 tarp in a ridgeline configuration. There are some great videos online on this configuration. I plan to use the rope supplied with my tarp by CCS. In many of the videos online it appears the rope used for the ridgeline and prussik lines is of a larger diameter than that supplied by CCS? Is there a reason for this or is this just personal preference? I have tied and used prussiks for climbing and have always used mountaineering diameter rope. I have never tied a prussik in small diameter rope but I assume it all works fine for a ridgeline setup. Thank you for your thoughts.

I just use the CCS cordage - it's fine; some people may prefer something else, but it will work fine for you.

CCS cord, at 1/8” diameter, is sufficient for a tarp’s ridge line. Slip and grip knots, such as the Prusik, work best when the diameter of the line used for the loop is smaller than that of the line to which it attaches. I use REI 3mm bulk cord for my ridge line (approx 1/8”), and a 2mm cord for my loop. I use the CCS cord that came with my tarp for the guy lines.

Note that while the Prusik works well in either direction, other knots, such as the Klemheist work better for loads which are always applied in the same direction, which is the case for a tarp and ridgeline setup.