Hope someone can help with this. I'm going to visit my parents next month and DD (6 months) will be sleeping in a travel cot for 10 nights. My mum has found a place that will cut foam to size so that we can get something a bit more comfortable than the very thin padding that comes with the travel cot. I was just gonna ask if anyone knows what density cot mattresses have to be but as I'm typing this I think I should probably ask, is this a sensible idea or should I really buy an approved mattress?