Jay, it mostly depends on whether or not you intend to publish the pattern. If not, call it what you will; if so, it's helpful for readers if you use something like the following: 1) if it's just a material/colour change use your own name, e.g., Jay's Pheasant Tail. 2) if there are other changes but it still retains a recognizable design, you may want to call it a variant, e.g., Jay's Pheasant Tail Variant. 3) if the "original" design is no longer recognizable, call it what you will but try to avoid obvious duplication with a quick Google search.
Just one thought. cheers Paul www.galesendpress.com -- Paul Marriner Outdoor Writing & Photography. Owner: Gale's End Press. Member: OWAA & OWC. Author of: A Compendium of Canadian Fly Patterns (co-author), Stillwater Fly Fishing: Tools & Tactics, How to Choose & Use Fly-tying Thread, Modern Atlantic Salmon Flies, Miramichi River Journal, Ausable River Journal, and Atlantic Salmon.
