Three views of the relationship between T and β for the background, from the MBB model. Left: PCCS2 background regions, which are at high Galactic latitude, are in green. PCCS2E Galactic mask regions, which have strong, dominant dust emission, are in red. Middle: colours show Galactic latitude. Right: colours show RELTH, a measure of the non-Gaussianity of the patch. The symbol size here is proportional to RELTH.