So here it is. Many times I see pictures of flies, usually nymphs or pupae of some type that the tyer has soaked in water and then lays it on his hand or puts it in the vice and says “Look how real this looks!” The fly does look real, when it’s wet and out of the water, but put it back in the water and that’s now how they look. I personally don’t think that it matters what they look like out of the water, it’s in or on the water that counts.
Rant over - thanks for readin’ 
That was a pretty mild rant. I suppose one would expect a mild, polite rant from a Canadian. 
Ed
Thank you - eh!
Flies out of the water are intended to catch fly fishers. Flies in the water are intended to catch fish. I suspect more fly fishers are ‘caught’ (meaning they see the fly and just have to have it) than fish are caught. I admit, I buy and tie some flies just because I want to or think they are pretty, and other flies because I know they will catch fish, if the fish cooperate that is.
Larry —sagefisher—
Aside from demonstrating the “shade” when wet vs dry for materials…the fish see everything different fro us either way.
If, for example, you tie a nice soft hackle with a nice partridge collar and DO realize that the fly will look (and behave) nothing like the fly in your vise…then it doesn’t matter.
However, if you aren’t aware that that collar will pulse and often drape the body when under stream flow, you might learn from putting it in a slant tank and pulling it through the water to observe it. In addition, most dubbing appears somewhat more dark in color when wet. If the insect sample you are imitating in the pre-emergent, or even a dry fly, body color is a certain shade in color, it is good to see whether the dry dubbing you applied takes the insect’s shade of color once the fly is wet…it often darkens up when wet.
It’s my experience that many (not all) materials will appear darker when wet in your hand than when wet in the water.
Why I suggested looking at it submerged in a slant tank…or any clear container