I'm looking to start my first rod and was wondering the pros and cons of each thread material.

I see a lot of people use silk or nylon, but is there any reason to stay away from polyester or cotton?

Nylon: easy to wrap, many rod building companies sell it, and many production rod companies use it. Your best bet if your doing you first rod.

Polyester: as far as I know, only one company is offering this type of thread for the rod building community, Fuji, real nice stuff and similar to Nylon. Just as a note, Fuji Size A is slightly larger in Diameter than Size A Nylon, its not much, but I can tell a difference.

Silk: Its not for the novice in my opinion. You need to get the tension of the wraps just right, too much tension and once the finish goes on, it really may not look all that great. Silk also has more "fuzzies" in it than Nylon or Polyester (they have almost none) and to remove these prior to finish, you need to use an Alcohol burner to remove them, singe them off. I say Alcohol burner (DNA, same as camp stove fuel) because it is a very clean burning fuel. Alcohol burners, well they can be dangerous in their own right for obvious reasons, so really use caution if you go down this route. Plenty of the Bamboo builders use them, so they can be safe as long as the operator pays attention to what they are doing. Keep a fire extinguisher handy. Silk is also used when you want your threads to go invisible, White Silk on "clear" Fiberglass and Natural Shade Silk on any other color blank.

Cotton: I do not know of any thread specific to rod building made from Cotton. You can use sewing thread, but this thread has Silicone in it so it will function thru a machine. You must seal this thread with color preserver prior to applying finish. The finish will "pull away" or give what most folks call "fish eyes" to the wrap finish. Best to stay away from Cotton.

As a beginner, get yourself some Size A Nylon. Regular nylon does give a real nice look, especially if you do not use Color Preserver. Just note that the thread will darken a bit, usually 2 shades darker (but this can depend on the base color of the blank you have to). If you want the actual color of the Nylon, just apply some color preserver, but the trade off is that the Nylon will loose some of that luster you'll achieve by not using it, trade off. They do sell NCP Nylon, this thread is "preserved already" and in my opinion, best suited to trim bands. On a full guide wrap, it looks like "flat paint" was used to attach the guides.

Fuji poly NCP will darken much less than nylon. It's nice when you want to get bright colors on dark blanks.

I've never wrapped a rod with nylon - I've always used silk. And like Tim, I've never had a problem with it. I've never needed to use a lamp to burn off fuzzies. I usually use two thin coats of TM Lite but I've also used spar a number of times. I don't use the finest gauge of silk, like gossamer, because I don't see any advantage to it other than maybe for trim bands or totally invisible wraps. Years ago I did a static stretch test comparing nylon to silk and found that nylon stretches way more than silk. Whether that translates into silk giving stronger reinforcement at the female ferrule I don't know - but probably not.

I started with bamboo as well using only gossamer silk. If you use good quality silk it is a real pleasure to work with. Not nearly as finicky as perhaps it used to be.

Hello
The Problem Isn't Necessarily The Thread But Often How The Thread Reacts When The Finish Is Applied.
I Like Silk And Nylon.
Have used and experimented with every thread you can imagine.
Still Like Silk and Nylon Best.
Tight Lines And Whatever Your Happy To Put Your Name On Loops
Andy M

Cotton rots when wet, silk and polyester don't.
Cotton doesn't have near the strength of either, and of course, silk is the strongest natural fiber extant.
If you look at tire cords for hand-glued bicycle tires (i.e., not vulcanized), silk and polyester are used interchangeably on road tires (at different price points), while cotton linen cord is a less expensive event tire - used once and thrown away.
Probably doesn't relate to rod wrapping, but silk cord is super-fine and soft 1000+ tpi, and polyester is linen size (still fine), 300+/- tpi.

this is an intestine thread, i think my experience with silk has only been the cheeper stuff and the fuzzies have turned me away from it. perhaps i will buy some more and try again.
i am a big fan of the Fuji threads, all of them have been great and take various finishes nicely.

The older Orvis I bought in 1964 when I was in college and have been fishing with it now for 55 years and the wraps look as good as when they came from the factory. The rod is a 7&1/2 ft Equinox and is as straight as an arrow and a great caster for everything from a dry fly to a bass popper. By the way, the price in 1964 was $50 delivered.