  The crease is a surface operator folded by a finite angle along an infinite
line. Several realisations of it in the 6d ${\mathcal N}=(2,0)$ theory are
studied here. It plays a role similar to the generalised quark-antiquark
potential, or the cusp anomalous dimension, in gauge theories. We identify a
finite quantity that can be studied despite the conformal anomalies ubiquitous
with surface operators and evaluate it in free field theory and in the
holographic dual. We also find a subtle difference between the infinite crease
and its conformal transform to a compact observable comprised of two glued
hemispheres, reminiscent of the circular Wilson loop. We prove by a novel
application of defect CFT techniques for the $SO(2,1)$ symmetry along the fold
that the near-BPS behaviour of the crease is determined as the derivative of
the compact observable with respect to its angle, as in the bremsstrahlung
function. We also comment about the lightlike limit of the crease in Minkowski
space.
