The GCLOSE subroutine is a graphical call that closes the current graphics segment. Once a segment is closed, no other primitives can be added to it. The next call to a graph-generating function begins building a new graphics segment. However, the GCLOSE subroutine does not have to be called explicitly to terminate a segment; the GOPEN subroutine causes GCLOSE to be called.

This call is part of the traditional graphics subsystem, which is no longer being developed.