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If you examine my various stamp images, you will notice that I have numerous screenshots of a computer program called EzGrader. A Canadian company called SoftPro 2010, based near Sault Ste. Marie, produces this software, and I find it extraordinarily useful and user friendly.
The EzGrader website, which is www.ezstamp.com/ezgrader/index.htm, touts the product with these words:
"EzGrader™ is a powerful new TOOL available to stamp collectors which allows you to easily determine the centering (i.e., Grades such as F, VF , XF ) and measure the perforations of your stamps."
And, indeed, the program accomplishes these goals with only a few mouse clicks.
Let us examine the output of EzGrader using a new United Nations issue, just to choose an example.
To begin, I am recording a screenshot of the original image of the stamp:
If you look at the path on the menu bar of the screen, you will see that this is a bmp file. This is the preferred file format for EzGrader because the bmp format does not compress the image. The program can also work on a jpg format — which I use through the rest of my website because such files consume far less disk space.
The next step is to run the analysis, which produces the following output:
Observe by looking at the thin colored lines how the program found the margins of the stamp.
Next, look at the screen providing important quantitative parameters regarding the stamp.
So, what do these numbers mean? Just before we address that question, look at the diagram that I have copied directly from EzGrader's user manual. This shows that the stamp margins lie between the orange lines and the red lines. EzGrader refers to the orange lines as the "stamp edge — the physical edge of the stamp, where the paper ends" but disregarding the perforation tips. The manual refers to the red lines as the frame edge, interior to which lies the stamp's design.
With this picture and these definitions in mind, we can discuss the output numbers.
1.a. The horizontal-centering output compares the left and right margins of the stamp by dividing the larger of the margins into the smaller of them and multiplying by 100. Hence, the left margin of our stamp is 94% the width of the right margin. We know that the left margin is the smaller of the two, because the stamp is "offset to left." Incidentally, if the left and right margins were exactly equal, then the horizontal-centering reading would be 100.
1.b. Similarly, the vertical-centering output compares the top and bottom margins of the stamp by dividing the larger of the margins into the smaller of them and multiplying by 100. Hence, the top margin of our stamp is 80% the width of the bottom margin. We know that the top margin is the smaller of the two, because the stamp is "offset to top." Again, if the top and bottom margins were exactly equal, then the vertical-centering reading would be 100.
2.a. Next look at the margin comparisons. Balance relates the sizes of the horizontal and vertical margins. Here, the user's manual provides a clear explanation:
"The Left and Right (Horizontal) margins are added, then compared with the sum of the Bottom and Top (Vertical) margins. In order to keep the rating in the range 0 - 100, the measurement is then the ratio of the smaller to the larger. The caption above the Balance rating will read 'Balance H/V' if the Horizontal sum is less than the Vertical, and 'Balance V/H' should Vertical be less than Horizontal."
As an example, the EzGrader user manual compares the following two hypothetical stamps. It notes that these two stamps "have identical designs" and "are very well centered," and that they both have boardwalk margins. But the stamp on the left has a balance of 30 (H/V) whereas the stamp on the right has a balance of 75 (H/V). Finally, the manual notes, the stamp on the right is to be preferred and EzGrader would give a poor grade to the stamp on the left.
Hence, for our stamp, the sum of the top and bottom margins amounts to 95% of the sum of the left and right margins. Now, if our stamp were perfectly balanced, the balance would be 100% — but 95% is still quite nice!
2.b. The output also shows how much of the entire stamp is given over to the margins. For our stamp, the total area of the margins comprises 10% of the stamp design. The EzGrader manual gives further hypothetical examples, as the following diagram that I have copied demonstrates.
Philatelists could debate what ratio provides the most esthetic margin area. Probably, we could all agree that somewhere in the vicinity of 20% or so provides a satisfying ratio of stamp design to total stamp area. Also note that if the perforations cut into the design, then the total area of the margins would comprise 0% of the stamp.
3. The margin ratios are straightforward. They provide the relative size of the margins, with the largest margin shown as 100 and the other three indicating their size relative to the largest. As the manual notes, "a perfectly balanced stamp would have margin ratios of 100% on each side."
For our stamp, the largest margin is the bottom one, the right margin is almost as large (97% to be exact), the left margin is 92% as big as the bottom one, and finally the top margin is the smallest of all, measuring only 79% as large as the bottom margin.
This type of detailed, but easily obtainable data, exemplifies why I find EzGrader such terrific software.
4. The edge ratio measures the horizontal frame length by the vertical frame length. The manual gives some examples of edge ratios for theoretical stamps, as shown in the next figure, which I have copied from the EzGrader manual:
Proceeding from left to right, the manual notes that the edge ratios for these stamps would be 1.02, 1.09, 1.53, and 0.59.
For our stamp, the edge ratio is 1.47.
Notice that, if the horizontal side were longer than the vertical side (that is, landscape), the edge ratio would be greater than one. This is the case for our stamp. If the horizontal side were shorter than the vertical side (that is, portrait), then the edge ratio would be less than one. If the stamp were perfectly square, the edge ratio would equal one.
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On the next page, we will discuss EzGrader's rating system, which it calls eGrade.