I went out overnight and noticed as I was pitching the tarp that there are white lines on one side of the black silnylon. I'll try to get a better picture of it, the pic I took didn't come out well. But the tarp has two parallel white lines that are not visible from the other side. I'm a little bemused by this, I've only had this a couple of months and used it on two overnight trips. I stuffed and restuffed it a few times and finally made a slightly bigger sack for it because the original was just too small for me to wrangle the tarp into. Does wear and tear happen in the pack too? I only thought of this just now - I've packed it in the outside pocket of the Osprey last trip, but this trip I threw the sack/tarp inside the pack under the hammock and the bear can. Maybe something was rubbing it through the sack? This was a completely black tarp until this weekend, I swear I'm not that oblivious to not notice til now.