But again, what do I know. I've only been tinting professionally in Kansas and Arizona since 1993.
Everyone has their experiences, and will do what works for them. I worked in the precision optics field for about a decade, which served the aerospace and scientific communities. You can get away with quite a lot where a vehicle window tint application is concerned, but when using PSA optical laminates in windows for optical assemblies, you have to be a bit anal about controlling as many of the variables as possible. You also have to bear in mind that some of the films we used cost more than a monitor, so we needed to be careful
. Any "haze" at all can cause blooming of imagery in this type of application, but would probably never be noticed with vehicle windows. I'm a bit curious as to the effect minute amounts of haze will have on a window for a CRT/LCD panel light source. But I would guess that it would be more noticeable in this type of application.
As for the Dawn thing, it's pretty universally avoided, not only by tinters, but also by sign makers when applying vinyl graphics / vehicle wraps. The same possible issues related to the adhesive also apply in that field. Some of the sign guys won't even use dish soap at all, preferring some of the more "made for the task" solutions which they believe are better. Whether they are or not, is a topic often debated, and the benefits of using the proper solutions may only be realized with specific adhesive compositions. But if it works for you and your customers don't have issues, go with what you know
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I don't get why someone would want to tint their own glass instead of buying glass that is already tinted?
Other than cost, you might be able to find a wider selection of transmission levels in tint, rather than having to select either ~30% or ~16%. Other than for those two reasons, I can't think of a benefit.
Would a diy tint job look as good as glass that was tinted during manufacture?
Definitely not.