Most stamp collectors house their collections in albums or stock books. Both have advantages and disadvantages.
By MATTHEW CRANDELL
Besides catalog value, this is the most important factor in judging a stamp's value to most people. Centering is how well the design of the stamp is centered within the perforations or edge of the stamp. I have included images of a stamp in each grade as I list the grades.
S - Superb: The design is very nearly perfectly centered within the perforations.
XF - Extremely Fine:
You can see the design is just towards the top, but still very nicely centered, almost perfect.
VF - Very Fine:
The design is further off from center, but still well away from the edge and very attractive.
F-VF - Fine to Very Fine:
The design is closer to the edge, but still well away. This is the most widely collected centering, good enough to be attractive, but not sky high in price.
F - Fine:
The design can be very close to the edge, but it cannot be cut by the perforations.
AVG - Average:
If the design is cut into by the perforations at all then the stamp is average.
The hardest thing about centering is that it is somewhat in the eye of the beholder. The above examples are stamps that I am personally grading and I believe I do a very fair job. Other collectors or dealers can look at the same stamps and grade the centering a little different.
When buying stamps, it is always a good idea to see pictures of stamps that the dealer has graded. Even if you cannot see the actual stamp you are buying you can look and see how that dealer grades his stamps and you can then make a judgment on how well centered the stamp you are buying is.
Also of note is when sellers try and claim their stamps are "XF for the issue", or "VF for the era" or some other similar statement to make their stamps sound better than they actually are. It is true that stamps from some issues or some eras are much harder to find well centered but stamps are not graded on a curve. An issue known for poor centering may have very few VF stamp in existance, and that boosts the price for the VF copies that are out there, but it should never boost a F stamp to VF status just because genuinely VF copies are rare. Stamp centering should be graded uniformly, with a blind eye towards what era or issue the stamps are from.