SDO/AIA 171 Å EUV intensity (left) across the loop is described by Model L (blue line) which includes a background trend described by a second order polynomial. The shaded regions represent the 99% confidence intervals for the intensity predicted by the model, with (red) and without (blue) modelled noise. The vertical dotted and dashed lines denote x₀ and x₀ ± R, respectively. The middle panel shows the histogram of normalised layer width ϵ based on 10⁵ samples. The vertical dotted and dashed lines denote the median value and the 95% credible interval, respectively. Loop density profiles (right) for Models L (solid), E (dashed), S (dotted), and G (dash-dot).