Elk/Deer Silhouette target

[Kerwin]

I want to make a silhouette target, out of cardboard, of an elk and deer to shoot my bow at.  I think it is important to know the size of and get use to shooting at that, to help sharpen my archery skills.  I have wanted to do this for some time.

My thought is to find a good picture of an elk/deer and cut it out.  Shine a flashlight on it creating a shadow that I can cut out a good silhouette from.

My question is how big should the silhouette be to create an accurate medium to large sized elk, mule deer and white tail deer?  The only way I can think to measure this would be, how many inches from the ground to the top of the back/shoulder?

Any help would be appreciated.