Woven wool felts are generally the better product choice when "flexibility with density" is the key phrase.   For example, a piece of woven felt (WF-1 that's 1/4" thick [Mfg. #1955H]) and a piece of pressed SAE F-1 of similar size, bent at a severe angle--90° or more--will reveal how much easier the woven product can be bent and how much more readily it snaps back without distortion. When you consider that WF-1 weighs nearly 25% more than pressed felt, you can understand one of the superior properties of woven wool felt.

Close tolerance capability is another prime consideration in the choice of a woven felt.  Woven felt tolerances are one half the tolerances of pressed felt, and for precision requirements can be held even closer than the published tolerances.

Wool felt is frequently used as a wicking agent for a wide variety of liquids, and this is another instance where woven products will make a better choice.   Visual magnification of the fibers comprising pressed and/or needled felt compared with woven felt clearly reveals the intricate weave within the woven product.  The weave greatly increases the tensile strength and reduces the chance of splitting.   Consequently, in almost every application for wicking, woven wool felt will outperform pressed counterparts.  Since there are so many variables in wicking, only testing can provide a final answer. 

Finally, resiliency is another key factor for woven felt.  All wool felts are resiliant because of the very nature of wool itself.  But in most cases, woven felts will retain this resiliency much longer than pressed felts.