My tip is to use sanded tile grout for ballast you can get black grout and grey grout and mix them to the color you want grout comes in many colors.
If the grout is too fine mix some sand in with, it if you do add sand you will have to glue it down without the sand all the grout needs is water.Haven’t tried this but N scale you could mix sanded grout (floor grout) with non sanded grout (wall grout). I’m in the states and grout is cheap sanded grout comes in 25lb bags wall grout In smaller bags . So you should have plenty off grout left for friends
“Started this with one idea in mind – mining and lumber mill – then added a reverse track for a little pusher car to go in and out of the mine, then added the first raised track, then the second, then another reverse track going from the mine drop-off to the processing shed, and on and on. 5 trains running on one piece of plywood!
That’s all folks – please do keep ’em coming. If you’ve got a layout – half built or beautifully finished – we’d all love to see it.
Just email me and I’ll do the rest. Latest ebay cheat sheet is here.