Sometimes people ask us, as why do they see some lines after the stretch. The answer to that question is, carpet has been left un attendant way too long before any repairs. What happens to the carpet is, the wrinkle not only creates a permanent damage to the underside of the carpet, but also dirt and grime gets collected in the area. The wrinkle also prevents the vacuum to do its job. Plus every time someone steps on it, it gets damaged.
Think of it as a cardboard. If you bend the cardboard, it will have a line, and it will never be the same. After the stretching is done, the carpet will be flat, but you might still see the line.
How to prevent the permanent lines
Once there is any sign of wrinkles in the carpet, one should call CarpetFix and get it fixed. We do require some furniture re arrangements. Like some small furniture or anything on the floor, should be removed from the room. We do understand that not every household have the capacity to remove all the furniture out of the room, but it should also be in a minimum state for the job to be completed successfully.
Can you show us some examples
If you look at the examples below, 1st picture is before, and the other two are after the stretch is done. Carpet is flat at the end, but you will see the line.