ballast

[CTValleyRR]

Find a couple of photos of your prototype, and that will give you a good guide.  Pay attention to how big the ballast pieces are compared to the tie cross section.

I used "Coarse" ballast on my layout, and while it looked good initially, I'm starting to feel that it looks too large.  It's about 6-8 scale inches, which is about 2-3 times the size of what is used on the prototype, except underneath on long fills.  Next time I do it, I will use "Fine" sized ballast.  This is probably a better guide than "HO" or "N" scales.

As far as performance, there is no difference.  It's for appearances only, and as long as you really lock it down with glue, it's fine.

[Aikidomaster]

Follow what the prototype does. It uses smaller size rails and ties that are farther apart. Also, you will notice that the sidings are not built as high as the mainline. There is usually a lot less ballast. Sometimes it is just dirt, cinders, and a small amount of ballast with a few weeds thrown in for good measure. I use a different color ballast for my sidings, generally, cinders. I use code 83 track for mainline and code 70 for sidings and yard tracks. I mix real dirt with the cinders and apply some Woodlandic Scenes ground form or mixed blend dirt/ grass. I also weather the track. Rust color with rail brown for the rails. I cut the ends of some of the ties. And I paint some of the ties with a light grey color. A bit of powdered chalk and you are done.

[baron9]

my question is is there a difference in what color and size is used for main line track as to sidings. I model in HO and use HO ballast for my main line track which is a grey medium blend. Is there a preference in using N scale ballast for sidings or keep it the same size for all tracks.