Another Take on Ballasting.

This piece of track is the fiddle yard of Roberts Micro Layout.
Because it is constructed of cardboard, it is not advisable to adopt the approach I have made on Teignford (Try Link).
Instead, PVA has been spread neat inbetween the sleepers and ballast added. Allowed to dry, the excess is brushed off leaving a well ballasted track.
This is ideal in this case and may be one you will try.