Abstract: Ink compositions are provided which are suitable for use in ink jet printing on coated or uncoated substrates to form images which are highly resistant to abrasion and penetration by virtue of the penetrating characteristics of a select solvent system. The ink compositions may be of the binder or binderless type and contain, in the preferred embodiments, from about 0.1% to about 5% by weight of a colorant, optionally, from about 3 to 30% by weight of a soluble resole resin, a penetrating solvent consisting of tetrahydrofuran, an auxiliary solvent comprising a lower aliphatic alcohol, ketone, ether or aliphatic amide, a surfactant and an electrolyte.