In Confusion Here About Flat Versus Rotary

I realize I think that rotary are either taller or wider than flat plate. My problem are with the measurements. Can flat plates be 19 1/2x 22 1/2 in other words around the 19's x 20's ??

The dimensions are the very last thing to consider, the tolerances are simply too small to be accurately measured (even with calipers). Inexperienced hobbyists tend to gravitate to using dimensions because they think them simple and definitive. (And then get all excited thinking they have a rarity after only using incorrect measurements.)

Use the other methods, outlined in a number of threads in this community or in these links
https://stampsmarter.org/learning/I...arities.html
https://stampsmarter.org/learning/M...methods.html

Don

I use the method of cutting the corners off cheap flat plate or rotary stamps and then compare.

PK,
Your question is fairly broad and general.
Please post a hi-resolution scan of the front AND back of a sample or two and we can take you through some of the high points. It's not all about measurement.

I appreciate all the replies and will post some pics. Was trying to understand what was written in H.E. Harris & Co " How to collect stamps " but left something to be desired. Still was informative.

The blocks appear to be flat, although the Franklin one cent is rotary. The three cent in an offset. The others are more difficult to tell from the scans, although I suspect they will turn out to be flat.

The blocks have flat plate plate numbers, they are 498 and 499.

IDing stamps with attached plate block numbers is typically easy, you simply do a lookup on the plate number itself.
https://stampsmarter.org/features/P...ockHome.html
(Click on 'Search By Plate Number' tab', enter your plate number, click on Search button).
Don

That's what I did.

Outstanding you've all gave me food for thought. Don I also downloaded those sites you sent. Jumped in and started reading and am enjoying the information. Thanks to all

Hi

There is a set of Colombia stamps that were printed both flat and rotary press. When in Colombia, the stamp dealer showed me how to tell the difference without any difficulty.

In general, obtain a known copy of both stamps, flat and rotary. Mount them and use it as a "template". Lay the questionable stamp on top of one of them, line up a corner, and one should be able to tell immediately.

Jerry B