How thin are they?

Thin scales,(some very thin), collarless pins, quality razor and the feel, No other scale feels like Ivory, It feels oily to me, like a polished finger nail, not just smooth, slippery.

There is a 60x lighted loupe that sells for a couple dollars, that has a white & UV light. UV & magnification make it a little easier to see the lines. Like Zak says the lines are hard to see on some.

The feel for me is the tell.