Is trimming a standard whiteboard always a bad idea?
Not always, for very minor adjustments handled professionally, but it is generally less durable than ordering a genuinely custom size.
Why does a trimmed edge perform worse over time?
A trimmed edge is harder to finish and seal properly on site compared with a factory-finished edge, making it more exposed to wear.
Does a custom-sized whiteboard cost more than trimming a standard one?
Usually yes upfront, but it avoids a weak point at the edge that a trimmed board carries for its entire life.
Can a trimmed edge be finished to the same standard as a factory edge?
It is difficult to match factory finishing on site, which is why a trimmed edge generally remains a weaker point long term.
When is trimming a reasonable option?
For a very minor size adjustment handled professionally, rather than as a general substitute for ordering the correct custom size.