[drcy]

It is possible for all cards to be found genuinely black backed. Printing errors or proofs. I pulled a blank back out of Topps packs as a kid. Considering Goudeys and similar cards were pasted into albums, you can also find them skinned.

I would think the best bet would be to card to various other 1934 Goudeys-- texture, etc. Skinned Old Judges are often simple to identify, because they pealed the paper thin photo off the cardboard backing. The skinned photo is perhaps 1/20th as thick as regular.

Forensically speaking, there are light meters that to 'point zero zero whatever' accuracy measure the opacity of material (how much light the material lets through). Might help aid in giving an opinion. I have one, but have never used one on a card.

For the record, there are even glossmeters that measure to 'point zero zero' the gloss of a material. The little metal machine shines light on a material surface (chrome, cardboard, whatever) at different angles and internally calculates the gloss from those readings. It gives you a reading, as if you're taking the temperature. It fits in your hand and resembles an old elementary school pencil sharpener. Paint and metal coating manufacturers use it industrially to test the gloss of their coatings. I have tested mine on baseball cards. Went through a stack of Topps and OPC once.

Most people can fairly accurately compare gloss and opacity of cards as far as identifying fakes go. One practicality of these tools is, in case of court or other dispute, they would give you black and white numerical results that can be double checked. Their readings aren't influenced by appraisal value, wishful thinking team affiliation or Miley Cyrus's twerking. Well, not much anyway.

But don't fret, I'll bring my glossmeter to the next National and rent it out by the quarter hour. For fun and entertainment. Duly note I am not liable if you try to measure the gloss of your eyeball. My lawyer says most judges in Ohio would say someone so stupid deserves to go blind in one eye. At they very least, first test it out on your dog or the neighbor's kid.

Hell, as long as you pay the $15 rental fee and return it in working order, I don't care what you do with it. Use it for as a screwdriver for all I care.

Actually, the light meter works better as a screw driver. The glossmeter is more of a paperweight/conversation piece.