Is stranded wire better than solid wire for modelling?
Deciding which wire to use when wiring a model railway can sometimes be a little overwhelming, there are so many choices between different colours, thicknesses and also whether to use stranded or solid core wire.
The good news is that a lot of these choices will not make a difference from an operational perspective, different colours are available purely to make your life easier in recognising different circuits when revisiting wiring at a later date or during a complicated build when specific wires need to be identified. The thickness of the wire is more important, but let's remember that we are operating model trains not real ones and a 7/0.2 wire or equivalent will be ample for most modelling feats with the possible exception of a very busy bus wire.
As for the dilemma between stranded and solid wire, the only tangible difference when using it to wire a model railway is its flexibility. Stranded wire is much more flexible than solid wire and the more strands it has the more durable it will be if it is to be bent or flexed a lot, so for most model related tasks, stranded wire is the wire of choice.