It sounds like you’re looking for vintage silk thread in size 00 or A, color Olive 11, specifically for wrapping bamboo fly rods. Here’s some helpful information:
Finding Vintage Silk Thread for Bamboo Fly Rods
1. Thread Size & Color
– Size 00 or A is a very fine thread, traditionally used for delicate wraps on bamboo rods.
– Olive 11 is a classic color, often used for tipping or wraps on vintage-style rods.
2. Where to Find It
– Vintage Tackle Shops – Some specialty dealers carry old stock of Pearsall’s Gossamer, Belding Corticelli, or Barbour’s linen thread.
– Online Auctions (eBay, etc.) – Search for “vintage silk fly rod thread” or “Pearsall’s Gossamer size 00 Olive.”
– Rod-Making Suppliers – Some modern suppliers carry reproductions or NOS (New Old Stock) silk thread.
– YLI Silk 100 (similar to size A)
– Gudebrod Silk (discontinued but sometimes available)

– Kimono Silk Thread (used as an alternative)
3. Modern Alternatives
– YLI Silk Thread (100 or 50) – A good substitute if vintage thread is unavailable.
– Raleigh Silk (Pearsall’s) – Still produced in limited colors.
– Belding Corticelli Silk – Occasionally found in old stock.
4. Tips for Restoration
– If using old silk, check for brittleness—apply a light coat of varnish or color preserver when wrapping.
– Some rod builders use Nylon or Polyester for durability but silk is preferred for authenticity.
Would you like help finding a specific supplier or verifying authenticity? Let me know how you plan to use the thread (restoration, new wraps, etc.), and I can refine recommendations.