Columbia Women's Trek Legging, Black, Small

I love how these leggings fit and they are really comfortable. But (big but) the material is very thin. I'm worried about how they will hold up with washing.

I don't know if this is a (Major) design flaw or if I just got a defective pair, but this is my first disappointment with a Columbia item. The fit is great, they are not super heavy, but decent, not flimsy cloth. But the flap on the phone pocket is sewn shut, so it can't be lifted to insert phone, and the pocket is rather small, so there is no way I would trust a phone not to fall out. I do most hiking with a half pack, or wearing a vest (I need phone & epi-pen on me at all times), so I guess I can use it for tissues, spare mask or keys. I don't want to pay to return, and I needed grey leggings, so I will be keeping them, but I can't recommend these at all. Pocket would be 5" high by 4" wide if not sewn completely down on both sides-pictured phone is 6.25" high & would fit with just an inch poking out.