The usefulness of linseed oil house paints depends so largely upon properties that fall clearly within the colloid domain that paint technology may properly be regarded as a branch of colloid chemistry. Bancroft has long treated paint from that point of view in his teaching at Cornell University, and research workers occasionally apply colloid theory and technic to paint problems. Nevertheless the writer feels that possibilities in that direction are greatly neglected, especially in studying the behavior of paint after it has been applied and aging begins. The object of this paper is to attempt to fit well-known characteristics of aging house paints hitherto considered in a strictly empirical fashion into a gradually developing colloid chemical conception of the phenomena. No new data are reported, nor are the theories advanced supported by any complete evidence. Justification for the discussion lies in the suggestion that the dominant characteristics of paint throughout its life ought to be brought within the scope of a coherent theory, and are interrelated in ways that cannot be suspected when the characteristics are considered seperately from an empirical point of view. A sound theoretical attack should greatly assist in accomplishing practical improvements that are urgently needed in the behavior of house paints.