The invention describes an improved thermally-responsive record material substantially free of aromatic isocyanate yielding an image of high intensity and useful for bar codes. The record material comprises a support having provided thereon a heat-sensitive composition comprising a substantially colorless color former comprising a fluoran; and a developer material selected from the group consisting of 4,4′-diaminodiphenylsulfone and 3,3′-diaminodiphenylsulfone, and an organic acid which upon being heated reacts with said color former to develop color, and including a binder material. Optionally, a modifier compound is included in the heat-sensitive composition. The compound can be selected from the group consisting of a fatty acid amide, such as stearmide. Optionally, magnesium state is included.