498 Perf Top Or Bottom?

What are your thoughts on this one? Appears to be a perf 10 on the bottom?

Mav... you really need to purchase a perf gauge,
which will enable you to get accurate measurements
on all of your stamps, and remove all of the guesswork...

Your stamp is perf 11 all around... standard 498...

Wow..I feel like a goof! I was counting the little gaps or spaces! I didn't know there was an actual measuring tool.

Yes, my friend... and here's one you can
start off with...

http://www.ebay.com/itm/Metal-Stamp...em48460fdd3c

There are really only two gauges that I'd recommend for US collectors. The Kiusalas (like the one below, although you should wait until someone lists one with the original book - that's important if you don't know which issues are 10-79, 10-80, etc.):

http://www.ebay.com/itm/360882222398

...or the Precision Gauge, which has a Kiusalas on it plus a lot more:

http://www.slingshotvenus.com/stamp...tyPerf5.html

I use both from time to time, but am becoming more partial to the Precision. I find their diameter gauge (measuring cancels) and transparent ruler (0.5mm accuracy for lengths of paper folds, plate cracks, etc.) to be very useful (more than the actual perf gauges.)

For someone learning, either of these gauges would be great starting points.

Remember that the Kiusalas is designed specifically for US stamps and is pretty tough to find with the original book (Canadian version available & even tougher to find.) The Precision is readily available & useful to collectors of any country (but many of the "extras" are specific to US issues.)

When I travel to view collections, I always have both of these in my bag.

I would recommend the simple black gauge (link provided by disi123) AND the precision multigauge (link provided immediately above). The former is great for fast simple work and easy on the eyes. I use that gauge 95% of the time for perf measurements. The precision is indispensable if you collect US AND to get more precise measurements than to the 1/2 gauge, as might be required for some countries or situations. As mentioned above it has other uses as well.

Wow! Thank you very much! Learning a lot!

I'll definitely be looking at the devices mentioned and buy this weekend. Thank everyone!

To make it a tad bit less of a mystery to Maverickx, the number 10 refers to the number of perforations in 2 centimeters length. So, you could use your counting method if you first measured off precisely 2 centimeters on the top or bottom and 2 centimeters on the side, then count the number of perforations within those 2 centimeters. If there are 13 1/2 perforations in 2 centimeters, perf 13 1/2, if 9 perforations in 2 centimeters, perforation 9.

But a gauge makes it a lot easier.

The catalogue perforations in 1/2 increments (sometimes 1/4 or 3/4) are approximations. The precision gauges linked above are designed to measure gradations between integers and 1/2 or 1/4 or 3/4. Real stamps often fail to match perfectly to 1/4 gradations. The catalogues have just rounded things off as best they can.

Thank you for the clarification, Hero!