Leon Drexler offers two weights of felt: the standard full weight and the lighter, softer Drexler Welterweight. The latter was so named (echoing the weight-class designation in boxing) because while not overall as light as a classic lightweight felt, it is nevertheless lighter than the full dress weight and, most crucially, lighter where it really matters—in the crown. This is achieved through a modification of the standard felt and is done in-house, and this offers certain advantages. First, it means that the welterweight option is readily available in any stock colour. Also, unique to this process, while the felt in the crown is lighter, more pliable and a little bit cooler, the brim retains the full standard weight with all of its structural advantages.

Stylistically, the welterweight is more suitable for some hats and less so for others. Generally, the best candidates are those styles intended for a more relaxed appearance, hats where you may wish to work in some idiosyncratic irregularity (Forager, Handicapper) as the thinner felt is considerably more receptive to such treatment. Less suitable are those hats where you may prefer to maintain a tidier, structural appearance (Stroller, Budapester), in which case a sturdier felt is preferred.
However, there is no firm rule and either option can be considered for most hats. Also, as this is a custom process done by hand, some variation in the degree of weight modification is possible.