Fig. 6
From: Properties of common tropical hardwoods for fretboard of string instruments
Wood nanoindentation hardness. The lower horizontal line of the inverted letter T is the minimum; the upper horizontal line of the letter T is maximum; the big square bottom edge represents the 1st quartile; the big square upper edge represents the 3rd quartile; the horizontal line inside the large square represents the median; small squares are average values; the *sign outside the box indicates an outlier