Question About German Reich Watermarks 2x And 2y

I am struggling with those watermarks (see picture from Michel catalogue). Sometimes I think I see 2 Y where it would be too good to be true. I wonder if somebody has a good advise on how to deal with this issue. Any suggestions please?

Well, two questions come to mind: 1) what are you using to look at/detect the watermarks? Fluid? Scope? Natural light? and 2) you're looking at the stamp in its "proper" orientation when observing, right?

Classic_paper - thanks, I possibly did not describe my problem accurately. I mostly use fluid (unless I can see WM clearly at natural light). I also have a scope, but somehow it is not helping me with the most difficult watermarks. In case of German WM 2X and 2Y there is no problems to see them clearly - usually they are very well visible even at natural light. My issue is that I cannot find the objective measure defining type X and Y. For example, on attached picture it seems that vertical size of two rectangular shapes is different, but in real life this criteria is very hard to use. So I just wonder what some other collectors using as the criteria.

the right lozenge group is more squarish..

I see. It is interesting that X and Y is not the same watermark rotated by 90 degree - they are actually different!