I’m working on a description of a specimen right now. It’s something I’ve seen before (since it’s not an IVPP specimen) and I have some notes on it and various photos, but without the material to hand, the basis of my description was on these notes and photos and not the material directly. Finally I’ve got hold of it again to try and polish it up and add in some more details. I hadn’t expected to have too much to go, but it was nearly instantly obviously that despite the notes and photos I’d made a couple of pretty bad errors. This was, naturally, the point of going back to the original material to check these kinds of things but it makes a point worth emphasising here.
There is simply no substitute for seeing a specimen firsthand and up close. It really doesn’t matter how good the descriptions, photos, drawings etc. are you will see things better and less ambiguously and more precisely in person. This is especially true of flattened things like from the Solnhofen and Liaoning. The ability to see things up close and turn them to the light just-so or switch between say left and right elements instantly can make a huge difference to your appreciation of the specimen and allow you to pick up things that would never otherwise get noted. It’s pretty much inevitably worth the effort and should always be a priority.