“Let’s just say that each material expresses itself in its own way. You have to let them speak.” In 1994, when the Catalan artist Antoni Tàpies made this comment, he had already exhibited 19 pieces that are now part of the Fundació’s current exhibition, “Profound Certainty.” Lifting the protective textile mats off his studio floor, stained and spattered as they were, Tàpies used them as the starting point for new paintings. Of what do they speak? Mortality. —E.C.