Posted By:
Al C.risafulli1938 Goudeys, particularly the DiMaggios, have been reproduced quite often. Unfortunately I've found that even astute prewar collectors get duped on a phony DiMaggio from time to time.
A couple of things to look for:
1) The back of a 1938 Goudey should be printed in green ink. Many of the reprints I've seen are printed in black ink.
2) The stock should be thick, similar to a 1933 Goudey. The cards should have no gloss at all.
3) The front of the cards should be uniform in the color of the stock. If you look at a '38 Goudey (shown below), you'll see that there's a border that runs around the card. The paper stock on both the outside and the inside of the border should be the same color - it's a plain, off-white color. Many of the reprints have WHITE stock on the outside of the border and off-white stock on the inside, or vice-versa. If the stock color is different on the inside than the outside, then you have a reprint.
The DiMaggio is one of the more important gum cards, and so the reprints seem to pop up pretty often. Be very careful if you're looking at a raw one on eBay.
Not how the stock color inside and outside the red border of this DiMaggio is the same color.
Also, there were several '38 Goudeys that were reprinted in that old baseball card book done by Dover Publishing. The words "A Dover Reprint" should appear along the bottom of the back of the card, in the center. If there's a scratch there, or if that portion of the card is otherwise obscured when you're looking at a scan, don't bid on it.
I've probably exchanged emails with ten different guys who have been duped by bad '38 DiMaggios over the last few years; just following the three rules above would have saved every one of them a headache.
And just so everyone knows, the first #274 DiMag that I bought was a fake as well. 
-Al