Measuring stamp designs is not straight forward or easy. First it takes a quality measuring device, many of the rulers found on perf gauges are not suitable. The process which a person measures becomes paramount, a first time measurer is not going to be proficient. Due to the scale of many rulers, the measurer must be consistent in determining the size.
Here is an example of a common mistake made when measuring. In the first illustration the 0 ruler marker is aligned to the middle of the left stamp design edge. The 24.5 end marker is also correctly aligned to the middle of the right edge of the stamp design.
But often inexperienced measurers will do as this illustration shows. They will incorrectly measure the stamp design starting at left side with ruler marker off to the right or left. But then on the right side read the ruler marker using a middle of the marker as shown here.
Key here is to be consistent when measuring. A better approach to cut up a stamp of comparable size or known dimensions to use as a template. For example, use a common flat plate stamp with the corner removed as a comparison scale 11 when trying to determine if a stamp is a flat or rotary issue. For coil waste issues you can cut up a common horizontal coil stamp as a template. See other SCF threads for more info on this.
Moving on, unfortunately the design measurements can be affected but many things (shrinkage, paper grain, etc.). Additionally the published measurements in Scott may or may not be accurate enough to make this determination.
You might also check the measurement between the rows of perforations. They should be as follows:
Between Vertical Rows: 20.5 mm, or more
Between Horizontal Rows: 24.0 mm, or more
Pay close attention to the perforations. The vertical perforations should be 11-72 on the Specialist gauge or 10.94 on the Instanta gauge. The horizontal perforations should be either the same as the vertical perforations or appear to be slightly wider, close to 11-73 (10.79) or between 11-73 and 11-72.
All of the above issues make the posting of only design measurement in a public forum fairly dubious. For a #544, understanding the perfs and color can be a big help. As previously stated, posting an image might assist an expert like Clark in helping you make a better identification.
Don
Edit: More info on making stamp templates,
An easy method to sort flat plate and rotary press stamps in quantity is to cut a damaged common flat plate stamp in half and use it as a template. Perf 12 Washington Franklins make good examples since they will always be flat plate. You will need two templates, one cut horizontally and one cut vertically, since the rotary press stamps can be longer in either direction, or you can make a single template with four cut corners, as in the picture above. Note that you can use any flat plate stamp of the same size as a template, it does not have to be of the same denomination or color, only the size matters. You might also want to make a rotary press template if you have a few beat up rotary press coils.
Posted 01/02/2016 10:54 pm
