An assortment of 30, 45 and 60 degree blades for the USCutter TITAN, TITAN 2 & TITAN 3 Series Vinyl Cutter.
The primary rationale for blades of different angles is cutting depth. A lower angle (45 degree) is great for thin materials, while a steeper angle (60 degrees) has a more vertical cutting orientation that penetrates deeper.
An increased amount of blade dragging through the material when cutting fine detail can cause, what they call, vinyl ears (parts lifted up). With minimal blade in the material, a 60 degree blade tends to cause fewer, if any, vinyl ears.
Using a 60 degree blade on everyday cutting is a waste of a blade, technically speaking. Less of the blade's cutting area is used, and blade life is wasted. The more horizontal cutting orientation of the 45 degree blade accurately distributes the cutting task over a larger blade area, and thus last longer (and is cheaper). So use a 45 degree blade always, unless a 60 degree blade is needed for thick or more custom types of cutting, if 45 degrees blades are not available.