Linen is used for rope, cloth, bandages, and wagons. It is plentiful on Myr but relatively scarce on Aerhen. If you ever get 50 at once outside of the starting area you are probably going to use it for the other purposes (bandages probably), not clothing. Otherwise it is fine.
Cotton is only farmable, thus gated by cities and crop rotations. Once we get vegetables and leafy greens I fully expect to never see a cotton field again. This is mainly due to its uselessness and pathetic stats. Other than the volcano on Aerhen there is no place where you would need the heat insulation, and even there you are probably running fire protection to avoid the stacks. Considering the dificulty to get it, uselessness of the product, and very limited uses it has, it is no wonder that most just throw it away as they harvest it. It only had a niche value when it gave +1 perception per armor piece... but those days are long gone and probably for the best.
Spider silk is the every mans go to. It is balanced for cold and heat, it has better armor and no encumbrance. This is your default material which everything else compares against.
Primal Weave improves energy damage and resistance to same. This is great for the... 2... mage damage spells that do that, or the ...2... charisma spells that use it, or the ...6?... utility spells which do some energy damage as a side bennefit to the main point of debuffing the targets. If you somehow make an AA build that is viable it may be nice for that mage favorite -mage staff-. It is still very niche and overshadowed by alternatives like:
Mammoth wool. This is one of the top 3 materials. It gives HP. It gives HP. It gives HP. there is also the nice synergy of increasing cold insulation and reducing heat which is opposite of scholars armor and results in a nice neutral, but higher net, insulation level for both. The shock and crush resist is also nice vs some mobs and some specific pvp builds.
Ghastly spider silk is an odd ball... if you -really- want one material for the widest range of enviroments i guess you could use this... but it has nothing much to reccomend it otherwise (unless Arborious uses lots more acid damage as we saw in the video, but even then you are likely to just use acid protection spell instead to avoid stacks). It is also a powerful enchanting reagent and probably better used there.
Rabbit wool cloth is a joke. Luck does very little now with most things resisted by fortitude not willpower and even then it being a scalar thing instead of a save-to-ignore thing. It is the consolation prize for killing a rabbit and getting no feet.
winterspine weave is a top 3 contender due to the pvp aspects with its damage reflection, cold resistance, and armor. The encumbrance is a slight downer, but is still a viable option.
TLDR:
Start with spider silk, graduate to mammoth wool, dabble in winterspine weave. Ignore the rest as useless. Cotton needs more uses, luck needs to be meaningful, and need more reason to use armor insulation instead of flat protection abilities when entering hostile enviroments. (see rant about how stack decay should be tied to elemental resistance instead of a seperate thing, which would then make armor material resistances and insulation more relevant)
All cloth armor materials are still pathetic in variety and utility when compared with the options available for leather and metals.
Yes this is for a good reason- namely the leathers and metals take more time and investment to obtain.
In alpha this was balanced -some- by giving cloth armors 3 enchantment slots instead of 2 -AND- assassins' armor was made from leather but still a light armor. So back then the light armor user had a better selection of options.
I would like to see cloth armor options increase in cost (time, resources, etc...) but also increase in effect or variety so that people have meaningful choices. Right now it certainly feels like we do not; winterspine or mammoth, flip a coin then choose mammoth for the hp.