A composition of a loose mass of comminuted raw cotton linter fibers has a bulk density of at least 8 g/100 ml and at least 50% of the fibers in the mass passes through a US standard sieve size #10 (2 mm opening). This composition is made by obtaining a loose mass of first cut, second cut, third cut, or mill runs raw cotton linters or mixtures thereof and comminuting the loose mass of raw cotton linters to a size wherein at least 50% pass through a US standard sieve size #10 (2 mm opening). This composition is used to make cellulose ether derivatives.