What drove the decision to swap fabrics? I was under the impression that Ultra Grid was having issues with delamination compared to normal Ultra or Ultra X.
Other way around.. UltraGrid never had issues, delam issue with Ultra200 was somewhat overblown by very few and should be a non-issue with newer 200x formula.. 200x is an amazing fabric.. Only Aluula Graflyte is slightly better IMO (100% UHMWPE), but that fabric has super limited availability.
Some facts on the Ultra fabrics:
UltraGrid is a New UL Pack Fabric from Challenge.
Challenge makes a few fabrics in the Ultra line. UltraWeave, UltraGrid and UltraStretch. Ultra is their brand name for the UHMWPE fiber used in the fabrics.
UHMWPE = Ultra High Molecular Weight Polyethylene aka: Dyneema, Spectra
UltraWeave is now well known as a premium pack fabric. It is 66% UHMWPE + 33% Recycled Polyester with a RUV film backing.
UltraGrid is newer. It is a woven ripstop with TWO 200d strands of UHMWPE (about 20%) + 210D recycled Nylon (about 80%) with a PU inside coating and a C0 DWR outside coating. 3.9oz sq/yd. Strength and abrasion resistance is very high. (.6 – 2oz LESS weight than similar 210D ripstop pack fabrics.)
UltraGrid costs less than UltraWeave, is faster to work with and has more color options. It has a unique look with the double UHMWPE black or white ripstop grid. It outperforms all other similar weight 210d ripstop nylon pack fabrics and is stronger and more abrasion resistant than all the other 210d single UHMWPE ripstop fabrics (and many heavier 400d) of various names.
UltraWeave is the premium and highest performance pack. UltraGrid is a lower cost option that looks great, works hard and will outperform all other similar weight pack materials except UltraWeave.