Unfused collar advice-custom shirts

I was hoping you guys could give me your thoughts on an issue I have been experiencing

Shirt collars puckering along the seam once I wash the shirt, the type of wrinkle that won't come out because there is a 'bubble' of fabric that simply get's pushed further along when you iron.

This is particularly evident in shirts I had custom made by Natty with an unfused soft collar.

Is this an issue to do with the collar interlining shrinking unevenly to the shirt fabric?

I have had a similar experience with Natty's unfused collar shirts.

First of all, I have to note that an unfused collar will always be more difficult to iron, as it will lose its proportions once washed and thus needs to be reshapen with the iron.

However, I've come across that Natty's unfused collar have the deforming problem you mention because of the very tedious tendency of their thread to shrink so badly, I don't know if your shirts have an interlining piece but mine didn't and this is another cause of poor collar shape. In TM Lewin shirts, which feature an unfused but moderately firm collar, the interlining allows the collar to look crisp (for a while...) after pressing and reshaping. Natty's collars are just two pieces of fabric sewin together so as soon as the thread shrinks, the edges get distorted. Further problems are caused by the low quality fabric, which shrinks like madness.

I manage to tame down some of the wrinkles by stretching the collar a lot along the edges, from the right side, but it will always look a bit rumpled. The same problem occurs in the armhole seam, which is never flat in Natty's shirts after the first wash.

Mine do have a linen interlining-Actually I suspect the interlining itself shrinks out of sync with the main fabric. Also thankfully it seems the oxford cloths do not have this problem-i suspect because they have some shrinkage compatibility with the interlining.

I suppose you get what you pay for to some extent, though I stick with them because they accommodate every little request I have with no complaints which is to their credit. I sent them an email about this and they were receptive to the criticism, though whether it will have any real impact remains to be seen.

I did not realize TM Lewin had unfused collars. I avoided them largely because they seem to be proponents of the spread collar which I have not yet warmed up to.

Saville Row Company seem to have some nice classic cloths and cuts, I might try them next.