Need Help With An Argentina Watermark

I have a copy of what could be either a Scott #221 or 270, a 10c gray green San Martin. However the watermark is neither #87 (honeycomb) nor #88 (multiple suns) as given in the catalog (2012 issue), but is clearly on paper with watermark #288, the RA in sun with straight rays. The best I can tell from the catalog, though, is that watermark #288 was not used before 1942. What am I missing?

Could #221 be #237?
#270 (1920) has a sun watermark as you describe. There, however, is the flat sun variety that may be #310 (1922). Maybe you are talking about the flat sun?

Maybe you can post pictures of the front and back, preferably scans.

Yes, definitely need pictures...

Ok, here some scans, not sure how they will appear here, not very experienced with stamp scans. I've enhanced the watermark.

Is that blue colour what you are seeing? Or did you enhance it? This appears like someone drew a watermark on the back of the stamp.

I used an image program to adjust the contrast on the stamp so the watermark would be more visible, resulting in the blue color of the watermark. I was concerned the watermark might not show up when posted here. I'll include the original scan below.

A guess: this stamp has perf. gauge 13 1/4 and not 13 1/4 x 12 1/2.
It is a 1922 Variant of #310, not listed by Scott.

Thought you had it there for a moment NSK, but the perfs measure 13 1/4 x 12 1/2.

Then it must be #310.

It is the flat sun watermark.

If the perfs are 13.25x12.5 it is Scott 310B, 310 is the 13.25x13.25 stamp. Both issued in 1922-23.

Gmot- Ok, thanks, my 2012 Scott doesn't list the 310B. Is that in a more recent issue of the Scott Standard catalog, or in the Classics specialized?

It's in both standard and classic 2021 editions. Not sure when they added the separate cataloguing for perfs for those series.

~Greg

Thanks so much for your help Greg, and NSK too. I will mount the stamp according to this new information. I am still a bit puzzled though about the watermark. Those 1922-23 issues are listed in Scott with watermark 90, which has an angular ray connecting the suns. The stamp we have been discussing has a straight ray connecting the suns, like watermark 288 in Scott.

The picture I posted has the same watermark as the 13 1/4 x 12 1/2. This watermark has straight rays connecting the flattened suns.

There's considerable variation in that watermark - sometimes the rays connect, other times not, sometimes look pretty straight, it started use in the 1920s. The "straight rays" watermark isn't used until 1942.

See picture from the Jalil specialized Argentina catalogue. At top - Sol Redondo (O) = wmk 90. At bottom - Sol con rayos rectos (R) = wmk 288. You can see a lot of variation in how the rays connect the suns in the top image.

Yes, thanks for the reminder NSK, I had forgotten to go back to that picture before I posted.

gmot, that picture from the Jalil catalog is a great help, and tells us that the way watermarks actually look is not always as cut and dried as the illustrations in Scott appear.

Really appreciate all of the information from both of you! It has been a great learning experience.