I bought a pair of cheap dark wash jeans from Sainsbury's but while they looked good on the hanger, as soon as there was a bit of tension on th fabric white lines have appeared all down the legs. They aren't marks, they are actually part of the fabric, and I'm assuming they are the Lycra/elastane threads. The jeans are def not to small, if anything they are slightly on the loose side. Tried on another pair from Oasis today (dark wash Lilies) and the same thing happened. I sized up just in case - they were far too big but same problem. I want my dark jeans to look dark! Any recommendations - don't want to spend more than £50 at the moment.