SAYATEX solution, in surface sizing, improves the bonding of loosely attached paper fibres and fillers. The burst, tensile and folding strength of untreated paper can be raised to the desired level. The picking resistance of off-set printing ink can be greatly improved. Where primary surface effects are desired, the holding of the paper to a controlled degree is required. For this reason, the viscosities of sizing solution used should generally approach the maximum viscosity practicable for the operation in question. This tends to minimise the size penetration for bond paper of good erasure resistance (a fairly tough film of starch upon the surface permits easy erasing of typed letters). For an increase in internal strength, the aim should be to obtain greater penetration in which case SAYATEX of lower viscosity may be preferable.

Surface sizing is accomplished by passing the web of paper between a pair of press rolls, arranged either vertically or horizontally. The pick up of SAYATEX will depend on viscosity, absorbency of the raw stock, and nip pressure between size press rolls. Usually the temperature at size press ranges from 50º to 60ºC and the concentration of SAYATEX varies form 5% to 10%. Heavier paper and kraft liners on board are surface treated, on the first of the two or more machine calendars, by a feed of starch solution from boxes.