latex was used in all tests at 10 parts based on 100 parts of pigment each paper coating type whether it was based upon 100 kaolin clay pigment or a mixture of kaolin with calcium carbonate was divided into several aliquots and to each of the aliquots was added various water soluble polymer additives and obas in the paper coating tests that used polyvinyl alcohol as the oba carrier it was necessary to cook the pva at 200 u00b0 f for at least 40 minutes in order to hydrate completely in the tests that used hec as the oba carrier it was not necessary to cook the hec in order to hydrate this latter polymer was instead added directly to the coating either in solution or in fluidized polymer suspension form and allowed to hydrate with stirring in situ which required only about 15 minutes two different obas were used in the study 4 4 39 bis triazinyl amino stilbene 2 2 39 disulfonic acid tetra and 4 4 39 bis2 sulfostyryl biphenyl dsbp for runnability purposes either sodium carboxymethylcellulose or sodium alginate was added to each paper coating to produce a brookfield viscosity of approximately 1500 cps as measured with an rvt viscometer 4 spindle at 100 rpm the prepared formulations were then coated onto rolls of commercial 62 paper using a laboratory dow u00ae coater serial 079 type 89b ss at various speeds to give a range of coat weights the finished coated paper was recovered and paper samples were selected from each of the tests that corresponded.