Also, unfused collars and cuffs are harder to iron, and really need to be done by hand. If an unfused shirt is pressed by a commercial laundry, 99% of the time, fairly serious wrinkles will pressed in to the collar and cuffs, usually near the edge stitching. Good hand pressing won't have that, because the presser will slowly smooth those wrinkles out.
Have to disagree with Manton, although I am not disagreeing on the substance of it; simple the surrounding facts. From about 1991 to 1998, I used to iron shirts for my parents', so I speak from a lot of experience. The reason that unfused collars come out badly on machine presses on commercial laundry is predominantly due to time spent (and to a much lesser bit, expertise). In fact, using a machine press for ironing collars is far superior to using a hand iron in 99% of the cases with regards to getting the unfused collar to come out completely unwrinkled. It's difficult to explain this without a physical comparison and demonstration, but the trick is to lay out the collar properly before pressing. Most unfused collars, even the really low quality shirts, have the three layers shrink at the same ratios, therefore, properly stretching out the fabric right before pressing means it will come out perfectly when done by a moderately experienced presser. And if they did shrink at different levels (usually the interlining shrinks more), the hand ironer will actually have to "cheat" by ironing the top layer stretching from one side, then doing the other side stretching the opposite way, leaving them floating after ironing instead of being laid flat like they should be. In those cases, wrinkles are mostly inevitable, although with ingenious stretching of the collars, you can even avoid those on a machine press. The reason this is not so is because shirts are loss leaders for most drycleaners, and they do everything imaginable to save costs. For example, the machine I worked on was a non-full body shirt presser, which had a realistic limit of 24 shirts/hour. Most commercial shirt plants use a body presser and a sleever, which increases production to about 60 for a single body, and 100 for a double body. Because the collar/cuff pressing part is done separately, and takes the most time when done right, almost every discount shirt plant (and almost all commercial shirt presses are indeed "discount") rushes these, which leads to wrinkles. If they spend and average of 10 seconds more for the collar/cuff, they can eliminate 90% of wrinkles in nonfused collars. If they spend 15 seconds, 99%. But people that do these jobs these days are minimum wage, and the managers all insist on speed over quality, mainly because it's the only realistic way to operate at the prices most places charge. My parents charged $1.50 per shirt from 1991 to 1996, which was probably around 95th percentile of all drycleaners the US. They had to raise it to $2.00, because they were losing too much money; and they lost money even at $2/shirt. Only reason the price was so low was because we had extremely high customer loyalty due to shirts, and it attracted more. And being a small store, we were able to keep production low (400/week at the highest). Only my dad, myself, and one presser that worked for us for 3 years ever worked on the shirts, and my father's insistence on quality really made a huge difference. They definitely come out better than hand ironing, in my opinion. Anyway, the point is that commercial laundries do mess up unfused collars, but it's not because it's impossible to get right, but because the shirts are not finished with an emphasis on quality. The economics simply can't allow it. There are rare exceptions, but very difficult to find in any case. And as a final catch, the wrinkles made by commercial laundries are by no means permanent. However, the only way to get them out is by using a machine press; hand irons simply do not generate the pressure and heat to get all the wrinkles out perfectly. And since no one presses collars correctly with a machine press, it just seems like it's permanent. It's a vicious cycle.