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This is NOT a complaint! But I noticed that my plaques had some rough edges from machine cutting in their production. Easily resolved with some wet-n-dry P180 > P400.
The plaque on the left is as supplied and the plaque on the right has had its edges smoothed by me...........
The trick is to lay the sandpaper down flat on a worktop and work the plaque against the static sandpaper, not work the sandpaper against a static plaque. this ensures a more even straight edge. Take extra care on the radius corners.