Other polysaccharides added to aqueous base borehole fluids to provide characteristics to the fluids other than increasing the low shear rate viscosity include: cellulose derivatives, such as carboxymethyl cellulose, hydroxyethyl cellulose, mixed ethers, and the like; starch derivatives such as carboxymethyl starch, hydroxyethyl starch, hydroxypropyl starch, mixed ethers, and the like, including t