Highly sensitive panchromatic B/W film with patented Tmax T-grain technologie. Very fine grain and high resolution. The sharpness, gray scale, shadow detail and exposure latitude are better with the Tri-X film. With T-Max you need to be very careful with the exposure. But for a 35mm 400 ISO film this one does have extremely fine grain. 30x40cm prints with invisible grain - only the Tmax and Ilford Delta 400 can manage that (when developed in a fine grain developer).