CHROMICIZED extruded collagen suture was used successfully in 363 patients who had a wide variety of operations.1 The suture was strong, smooth, and pliable. Knots could be tied and seated easily because of the good degree of resiliency of the suture. Fraying and breaking occurred infrequently. Greater uniformity of size permitted a smaller size to be used in comparison with catgut suture. The extruded collagen suture gave the surgeon a dependable material which could be used confidently in operations. Many surgeons prefer to use a plain type of suture in the subcutaneous tissues. Although such tissues tolerated the chromicized suture nicely, a study of the plain suture was undertaken to determine if it also was a desirable suture. The plain extruded collagen suture is made in the same way as its chromicized counterpart except that the tanning process is omitted. The deep flexor tendons of cattle are sliced, digested