What is meant by "basis" in "... its basis in particles leads to a material comprising crystallites or grains tightly bound together, ..."?
The author is attempting to indicate that the &quot;paste&quot; is a suspension of particles that aggregate as it dries (ie the liquid portion evaporates), in contrast to a solution of a dissolved solid that recrystallizes as the solvent evaporates. Because the particles never dissolve, there is no possibility for a single crystal to form that is any larger than an already existing particle. Therefore, the resulting solid is necessarily composed of many small crystals/particles with boundary zones between them, rather than having a large scale uniform structure.