Bolsters
Bolsters are small decorative inserts fitted in between the handle and the blade, "bolstering" the blade away from
the handle. Often seen in older style knives.  The Blunt, Old French, and New French blades pictured above each
have a bolster, the Modern style does not.
Just like everything else, the shape of a knife blade has gone in and out of fashion.  Blunt
and Old French Blade styles in old patterns were normally originally made with silverplated
blades.  Today, these blades are made with a brushed stainless steel which mimics a
silverplated blade's appearance.  Below is a breakdown of the four types of knife blades.  
Blunt Blade
The oldest of the knife blade styles with straight sides
and evenly rounded tip.  Rarely seen in modern flatware
patterns.
Old French Blade
Straight on one sight with a slight upward curve towards
the tip.  Rarely seen in modern flatware patterns.
New French Blade
Both sides of the blade slightly curve upward, with an
indentation to the blade where the cutting side meets the
handle.  The cutting edge has a slight S shape.
Modern Blade
Both sides of the blade slightly curve upward, and, unlike
the New French Blade, has no indentation where the
blade meets the handle.  The cutting side is C shaped.