It is well known that feeding excess linoleic acid, which is preferentially deposited, has the effect of producing soft backfat in pigs. However, the firmness of this adipose tissue, as measured by mechanical probe, can often be better related to the proportion of stearate in the lipid than to linoleate. This study attempted to harden the backfat of bacon pigs by feeding a high-fat diet containing a high concentration of stearate. For comparison, pigs were fed a diet similar in all respects including linoleic acid concentration, except that the proportion of stearate was low, while that of oleate - the most abundant fatty acid in backfat, but previously found to be of low importance for its mechanical consistency - was high.