Avbstamps

Victor Bove, serving collectors since 1960

Luminescents on Stamps

U.S. stamps have various styles of luminescents, and Scott minor varieties are often distinguished by the specific luminescent methods used. This information, extracted from the BIA May 2000 article, identifies the different luminescent methods used on U.S. stamps, and ways in which those methods can be identified.

Overall Tagging (OV) is a general name that includes any stamps that are completely tagged by coating the stamps surface with tag after the stamp has been printed. This includes the earlier types I, II, IIa, and III, as well as later stamps that are completely tagged after printing by any of the current presses.

OV tagging is produced by applying the tag over a stamp's printed image. The selvedge of OV tagged stamps may be either tagged or untagged, depending upon the width of the tagging roller or blanket. This more descriptive term was needed to differentiate pre-phosphorous papers (uncoated paper (UP) and Coated Paper (CP)), from overall tagging types.

OV, UP, and CP tagged stamps appear at first glance to look the same under ultraviolet (UV) light, but they can be distinguished from one an other. Separating UP from CP stamps is discussed along with their definitions under Pre-phosphorous Paper (PP) tagging.

You need a few items to differentiate between OV and PP tagged stamps. The most important item is a good ultraviolet lamp with ample power. RayTech products are excellent. A lamp with sufficient power will cost a minimum of about $170.00 (as of December, 2006). You' ll also need a soft vinyl eraser, an 8- to 10-power magnifying glass and a large low-powered magnifying glass.

I use two lamps - a RayTech LS 7 and a Versalume by RayTech (or Scott Micro battery powered portable when I am on the road). Any other cheap portable lamps have proven to be a disappointment to me. Cheap lamps fail to filter out much of the spurious white light that the UV bulb produce along with the short wave UV light. This white light can mask weak tagging and also makes it impossible to separate OV from PP tagging, particularly if the paper fluoresces brightly.

An example of OV tagging is Scott #1854 11¢ Partridge. Examples of uncoated paper (UP) tagging are Scott #2184 29¢ Warren and #2186 35¢ Chavez. Examples of coated paper (CP) tagging are Scott #2933 32¢ Hershey and Scott #2185 29¢ Jefferson.


Stamp under visible light	Stamps under short-wave UV light
Figure I. OV tagging. Entire stamp is tagged.

OV and CP stamps can most easily be distinguished by rubbing the stamps' tagged surfaces a few times with your fingers, using medium pressure. OV tagged stamps always leave a heavy residue of tagging on your fingers, which is easy to see under UV light. CP stamps transfer very little or no luminescent material to your fingers. This is a definitive method for separating CP, and OV stamps without damaging them. UP tagging transfers some material, but a much smaller amount than OV. The rougher surface of the UP (compared to CP) causes the extra tag transfer. The mottled tagging of UP is very distinctive. UP stamps can be distinguished from OV mottled tagging and CP by this feature alone.

It is very helpful to identify and set aside reference copies of these three tagging methods, for studying their characteristics and identifying other issues. I recommend using Scott #2933 for CP, #2940 for grainy CP, #2186 for UP, and #1854 for OV.

Dull tagged OV and CP copies on fluorescent bright paper are the most difficult to differentiate. Remember the tagged stamps with any selvage that is not tagged cannot be CP tagging. CP stamps will always have completely tagged selvages.