What's wrong with this picture?
There are 35 stamp spaces covering a page and a half in Big Blue for the Belgium Parcel Post 1923-31 issue. O.K., a challenge but really it's just a matter of putting them in. Right? But what's this? A green 10c? My 2011 Scott Classic says vermilion. Oh, here's a 30c., a "brown-violet"? Looks sort of O.K., I'll put it in. Wait, this other album has one that actually looks violet-like, rather than that brownish color. Let me check the Scott Classic again to make sure there is not another issue. Well, there is a "B inside a oval" overprint issue printed in 1940; but hard to mistake those, and besides the colors are the same. Uh?
.......light bulb slowly turning on.......
I guess I had better check for issues newer than 1940... Lets see...What's this? Scott Q239-262 1941 (Types of 1923-40).
Yes, a 1941 24 stamp issue the same as "1923-31" in Big Blue, except differing in color. The "goats".
I compared all the denominations, and their colors, and fortunately MOST of the 1941 issues differ significantly. So all one needs to do is pay particular attention to the colors for the "1923-31" issue, and few mistakes should be made.
Here are possible troublemakers...
a)30c brown violet (correct) from 30c fawn ('41 issue)
b)5fr brown violet (correct) from 5fr rose lilac ('41 issue)
c) 60c orange (correct) from 80c orange ('41 issue)
The larger problem is most Big Blues- at least the ones I've acquired- have many of the '41 issues plastered in or around the stamp spaces.. Be aware.
So how does a proper "1923-31" album look?
The "sheep" resting comfortably in their assigned "1923-31" spaces.