<p>Provided is a disk roll substrate containing 5 wt% or less of 45 µm or larger shot and comprising 20 to 38 wt% of alumina silicate fibers containing between 40 and 60 wt% of alumina and between 40 and 60 wt% of silica; 10 to 30 wt% of kibushi clay; 2 to 20 wt% of bentonite, and 20 to 40 wt% of mica.</p>
