  Non-topological defects such as grain boundaries abound in pattern forming
systems, arising from local variations of pattern properties such as amplitude,
wavelength, orientation, etc. We introduce the idea of treating such
non-topological defects as spatially localised structures that are embedded in
a background pattern, instead of treating them in an amplitude-phase
decomposition. Using the two-dimensional quadratic-cubic Swift--Hohenberg
equation as an example we obtain fully nonlinear equilibria that contain grain
boundaries which are closed curves containing multiple penta-hepta defects
separating regions of hexagons with different orientations. These states arise
from local orientation mismatch between two stable hexagon patterns, one of
which forms the localised grain and the other its background, and do not
require a subcritical bifurcation connecting them. Multiple robust isolas that
span a wide range of parameters are obtained even in the absence of a unique
Maxwell point, underlining the importance of retaining pinning when analysing
patterns with defects, an effect omitted from the amplitude-phase description.
