Scientific Anglers Amplitude Smooth Infinity Line

Scientific Anglers


Scientific Anglers' Amplitude Smooth Infinity fly lines were an instant hit with us here at Pacific Fly Fishers.  The Amplitude Smooth Infinity lines sound like just another fly line when you read about them... with promises of slickness, floatation, etc.  There is something special about this line, though, and it is a casting dream on most fly rods. 

The Amplitude Smooth Infinity fly lines feature SA's AST Plus slickness additive which is a big part of the success of this line.  Slickness and durability are the benefits from AST Plus and you'll notice the slickness right out of the gate.  As for durability, the lines we've been using to demo rods for the last year are still doing great, and that says a lot!

The SA Amplitude Smooth Infinity fly lines are smooth, non-textured fly lines. Fly lines without texture cast much more silently and are preferred by many anglers.  The Amplitude Smooth Infinity provides the benefit of AST Plus but without the feel and sound of textured lines.

The taper on the Amplitude Smooth Infinity, called the Infinity taper, is extremely versatile.  The longer head design is perfect for mending at a distance and for good casters that like to aerialize some line during the cast. A fairly short front taper turns over streamers and strike indicators like no big deal but still has the delicacy left for small dry flies in skinny water.  

The Amplitude Smooth Infinity line is a half-size heavy like many popular lines today.  This half-size heavy feature makes the line very nice to cast on the many medium-fast to fast fly rods on the market today.  Put the Amplitude Smooth Infinity on your favorite rod and watch all these features come together in an awesome casting and fishing line.

The color of the Amplitude Smooth Infinity line is three different colors:  Optic Green, Mist Green, and Buckskin on the tip.

Here is what Scientific Anglers has to say about their Amplitude Smooth Infinity fly line:

The Amplitude Smooth series of lines are, simply put, the highest-performance smooth fly lines in the world. With up to five times less drag and eight times the durability of traditional lines, this will change the way you look at fly line performance.

The conventional wisdom in fly fishing is that there’s no such thing as a “do it all” freshwater line. We have something to say about that. The Amplitude Smooth Infinity has the power to bomb out streamers, yet retains delicacy for dry flies. It mends like an absolute dream, and delivers flies at all distances. Built a half-size heavy, with a long head and substantial front taper, it’s perfect for everything from trout and panfish to pike and steelhead. There’s a reason we call it the Infinity: there is no end to what you’ll be able to do with it.

  • Revolutionary AST Plus slickness additive for superior shooting ability and increase durability
  • Extremely versatile general-purpose taper designed for most freshwater species; an excellent line for trout, grayling, panfish, bass, carp, steelhead, salmon, and pike
  • Made a half-size heavy to load fast-action rods, but works well with a variety of rod actions
  • Extended head length for long-distance casts and superior mending ability
  • Triple-tone color design for easy identification of line distance and casting control
  • For use in moderate and cold climates
  • Braided multifilament core
  • Built-in loops on both ends for easy rigging to backing and leaders
Scientific Anglers Amplitude Smooth Infinity Fly Line Taper
Scientific Anglers
Line Weight
47' / 14,3m 90' / 27,5m 110gr / 7,2g
48' / 14,6m 90' / 27,5m 130gr / 8,5g
49' / 14,9m 90' / 27,5m 150gr / 9,8g
50' / 15,2m 90' / 27,5m 175gr / 11,2g
51' / 15,5m 90' / 27,5m 200gr / 12,8g
52' / 15,8m 90' / 27,5m 225gr / 14,5g
53' / 16,2m 90' / 27,5m 260gr / 16,9g

* Grain weight for the first 30ft