parachute adams, the post was made using white antron. I used that when i first started but now that I have more fly tying material I tend to use calf tail.
These step by step instructions on how to tie a parachute post are again by Chris Hatcher from www.questoutdoors.net
white antron, calf tail or substitute.
1. Start the thread and wrap back about 1/3 the shank length
2. Place the post material above the shank and put 2-3 wraps to secure it to the top of the shank. The left over material to the rear can now be trimmed. Since mayfly bodies are tapered, make an angled cut. This will eliminate ta lump of material that would need to be covered later.
3. Make wraps over the material that was left over from trimming and advance the thread in front of the post. Wrap thread in front of the tie in point, building a tapered mount. If done properly this will hold the material upright.
4. Bring the thread up the post by starting at the base and wrapping upwards. Make tight successive wraps up then back down onto the shank. This distance you wrap up the post depends on how much hackle is used.