A suture system spool is configured to retain suture having a suture diameter and tension the suture between a distal and proximal end portions of a suturing tool. The spool includes a monolithically formed disc defining a central opening that provides the disc with an inside diameter. The disc includes a base and a flap joined with the base at the inside diameter, and the flap extends from the inside diameter to an outer periphery of the disc to define a cavity between the flap and the base. The flap is spaced away from the base at a location between the inside diameter and the outer periphery of the disc by a factor of at least two times the suture diameter, and the flap is spaced away from the base at the outer periphery of the disc by a distance that is approximately equal to the suture diameter.