If you have a new reel or spool to fill, grab yourself a spool of the Airflo No Frills Backing, an 20lb, thin diameter backing that could help you
Rio 100yds 20lb Fly Line Backing (10 Color Options)
Durable - Extremely abrasion-resistant and features high strength and low stretch. (50 to 100 yards of 20-lb backing is generally reserved for panfish
Fly Line Backing 20LB 30LB 100 Yds for Trout Fishing (Orange White Fluorescent Yellow)-2PCS
FLY LINES & BACKING — Rod And Tackle Limited
Fly Lines, Fishing Lines, Fluorocarbon Leader
Fly line backing serves two basic purposes. The first is to fill up your reel so that your fly line completes the filling of your reel to within, say,
Micro Poly Backing Line - 20lb 100yd
Fly Lines - Products
Fly Lines and Fly Line Backing - Fly Lines, Leaders & Fluorocarbon - My Fishing Flies
Orvis Dacron Fly Line Backing, Orvis Backing Line
Airflo Micro Backing 20lb : 100yds – Glasgow Angling Centre