Note that many of the images look the same, since the distinction between them is
the tagging (or lack thereof), which is visible only under UV light;
or the gum, which is visible only from the back;
or some subtle design variation detectable only with precise measurements.

Image & Scott No.	Denom.	Design and PC/SI	Year	Press	Tagging	Gum	Plate Nos.	Key Features (Printer)	Retail Price
Transportation Series
1897	1¢	Omnibus I	1983	Cott.	0'all	Dull	1-6	(small "1¢")	.40
2225	"	II	1986	B	Block	Dull	1,2	(large "1")	.55
2225a	"	II	1990	B/C	None	Dull	2,3	(large "1")	.60
1897A	2¢	Locomotive I	1982	Cott.	0'all	Dull	2-4,6,8,10	(small "2¢")	.50
2226	"	II	1987	B	Block	Dull	1	(large "2")	.60
2226v	"	II	1994	C/D	None	Dull	2	(large "2")	.70
1898	3¢	Handcar	1983	Cott.	0'all	Dull	1-4		.65
2252	3¢	Conestoga	1988	B	Block	Dull	1		.90
2252a	"	"	1991	C/D	None	Dull	2,3		1.00
2252av	"	"	1995	C/D	None	Shiny	3		1.00
2123	3.4¢	School Bus	1985	Cott.	0'all	Dull	1,2		.90
2123a	"	PC	1985	Cott.	None	Dull	1,2		5.00
1898A	4¢	Stagecoach I	1982	Cott.	0'all	Dull	1-6	(letters 19½ mm)	.90
1898Ab	"	I PC	1982	Cott.	None	Dull	3-6	(letters 19½ mm)	6.00
2228	"	II	1986	B	Block	Dull	1	(letters 18 mm)	1.00
2228a	"	II	1990	B	0'all	Dull	1	(letters 18 mm)	12.50
2451	4¢	Steam Carriage	1991	C/D	0'all	Dull	1		1.00
2451b	"	"	1991	C/D	None	Dull	1		1.10
2124	4.9¢	Buckboard	1985	Cott.	0'all	Dull	3,4		.90
2124a	"	PC	1985	Cott.	None	Dull	1-6		1.40
1899	5¢	Motorcycle	1983	Cott.	0'all	Dull	1-4		1.00
2253	5¢	Milk Wagon	1987	B	Block	Dull	1		1.10
2452	5¢	Circus Wagon I	1990	B	0'all	Dull	1	(yellow paper)	1.50
2452a	"	I	1991	B	None	Dull	1	(yellow paper)	1.45
2452B	"	II	1992	Grav.	None	LG	A1,A2	(white paper)	1.50
2452Bv	"	II	1994	Grav.	None	LG	A3	(ink glows under UV)	1.50
2452D	"	III	1995	Grav.	None	LG	S1	("5¢")	1.50
2453	5¢	Canoe I SI	1991	C	None	Dull	1-3	(brown ink)	1.50
2454	"	II SI	1991	Grav.	None	Shiny	S11	(orange ink)	1.20
2454v	"	II SI	1993	Grav.	None	LG	S11	(orange ink)	1.80
1900	5.2¢	Sleigh SI	1983	Cott.	0'all	Dull	1-3, 5		8.50
1900a	"	SI+PC	1983	Cott.	None	Dull	1-6		12.00
2254	5.3¢	Elevator SI	1988	B	None	Dull	1		1.00
2125	5.5¢	Star Route Truck	1986	B	Block	Dull	1		1.60
2125a	"	SI	1986	B	None	Dull	1,2		1.50
1901	5.9¢	Bicycle SI	1982	Cott.	0'all	Dull	3,4		15.00
1901a	"	SI+PC	1982	Cott.	None	Dull	3-6		25.00
2126	6¢	Tricycle	1985	B	Block	Dull	1		1.10
2126a	"	PC	1985	B	None	Dull	1,2		1.30
2127	7.1¢	Tractor	1987	B	Block	Dull	1		2.00
2127a	"	SI-a	1987	B	None	Dull	1	(nonprofit)	3.00
2127b	"	SI-b	1989	B	None	Dull	1	(5-digit + 4)	1.60
1902	7.4¢	Baby Buggy	1984	B	Block	Dull	2		8.50
1902a	"	PC	1984	B	None	Dull	2		3.50
2255	7.6¢	Carreta SI	1988	B	None	Dull	1-3		1.75
2128	8.3¢	Ambulance I	1985	Cott.	0'all	Dull	1,2	(letters 18½ mm)	1.25
2128a	"	I PC	1985	Cott.	None	Dull	1-4	(letters 18½ mm)	1.35
2231	"	II PC	1986	B	None	Dull	1,2	(letters 18 mm)	3.00
2256	8.4¢	Wheel Chair SI	1988	B/C	None	Dull	1-3		1.80
2129	8.5¢	Tow Truck	1987	B	Block	Dull	1		2.60
2129a	"	SI	1987	B	None	Dull	1,2		2.60
1903	9.3¢	Mail Wagon SI	1981	Cott.	0'all	Dull	1-6	carmine rose	12.50
1903v	"	SI	1981	Cott.	0'all	Dull	3,4	brownish rose	30.00
1903a	"	SI+PC	1981	Cott.	None	Dull	1-6, 8	carmine rose	14.50
1903av	"	SI+PC	1981	Cott.	None	Dull	3,4	brownish rose	25.00
2257	10¢	Canal Boat	1987	B	Block	Dull	1		1.50
2257a	"	"	1992	B	0'all	Dull	1		4.25
2257v	"	"	1993	B/C/D	EP	Shiny	1,2		3.00
2457	10¢	Tractor Trailer I SI	1991	C/D	None	Dull	1	(yellow paper)	1.75
2458	"	II SI	1994	Grav.	None	LG	11,22	(white paper)	2.00
2130	10.1¢	Oil Wagon	1985	B	Block	Dull	1		2.25
2130a	"	PC	1985	B	None	Dull	1,2		2.25
2130b	"	SI	1988	B	None	Dull	2,3		2.00
1904	10.9¢	Hansom Cab SI	1982	Cott.	0'all	Dull	1,2		28.00
1904a	"	SI+PC	1982	Cott.	None	Dull	1-4		27.00
1905	11¢	Railroad Caboose SI	1984	B	Block	Dull	1		4.00
1905a	"	SI+PC	1984	B	None	Dull	1		3.00
1905av	"	SI	1991	C/D	None	Dull	2		2.00
2131	11¢	Stutz Bearcat	1985	Cott.	0'all	Dull	1-4		1.40
2132	12¢	Stanley Steamer I	1985	Cott.	0'all	Dull	1,2	(letters 18 mm)	1.75
2132a	"	I PC	1985	Cott.	None	Dull	1,2	(letters 18 mm)	1.75
2132b	"	II PC	1987	B	None	Dull	1	(letters 17½ mm)	19.00
2133	12.5¢	Pushcart	1985	B	Block	Dull	1,2		2.65
2133a	"	PC	1985	B	None	Dull	1,2		2.70
2258	13¢	Patrol Wagon SI	1988	B	None	Dull	1		2.45
2259	13.2¢	Coal Car SI	1988	B	None	Dull	1,2		2.45
2134	14¢	Iceboat I	1985	Cott.	0'all	Dull	1-4	(letters 18 mm)	2.25
2134b	"	II	1986	B	Block	Dull	2	(letters 17½ mm)	3.30
2260	15¢	Tugboat	1988	B	Block	Dull	1,2		1.80
2260a	"	"	1990	B	0'all	Dull	2		2.90
2261	16.7¢	Popcorn Wagon SI	1988	B	None	Dull	1,2		2.50
1906	17¢	Electric Auto	1981	Cott.	0'all	Dull	1-7		2.00
1906a	"	PC-A	1981	Cott.	None	Dull	3-7	("Presorted" 11.3 mm)	2.10
1906av	"	PC-B	1981	Cott.	None	Dull	3-6	("Presorted" 12.8 mm)	15.00
1906avv	"	PC-C	1981	Cott.	None	Dull	1-5, 7	("Presorted" 13.4 mm)	18.50
2135	17¢	Dog Sled	1986	B	Block	Dull	2		3.00
2262	17.5¢	Racing Car	1987	B	Block	Dull	1		3.00
2262a	"	SI	1987	B	None	Dull	1		3.10
1907	18¢	Surrey	1981	Cott.	0'all	Dull	1-18		3.00
1908	20¢	Fire Pumper	1981	Cott.	0'all	Dull	1-16		2.50
2263	20¢	Cable Car	1988	C/D	Block I	Dull	1,2	(Tagging 20.5 x 23.5 mm	2.60
2263v	"	"	1988	C/D	Block 11	Dull	2	(Tagging 19 x 22 mm)	2.60
2263b	"	"	1990	C/D	0'all	Dull	2		4.00
2463	20¢	Cog Railway	1995	C	EP	Shiny	1,2		3.00
2264	20.5¢	Fire Engine SI	1988	B	None	Dull	1		3.00
2265	21¢	RR Mail Car SI	1988	B/C	None	Dull	1,2		3.00
2464	23¢	Lunch Wagon	1991	C	SP	Dull	2,3		3.50
2464v	"	"	1992	C	EP	Dull	3		4.00
2464vv	"	"	1993	C	EP	Shiny	3		4.00
2266	24.1¢	Tandem Bike SI	1988	B	None	Dull	1		3.50
2136	25¢	Bread Wagon	1986	B	Block	Dull	1,5	(reddish)	3.50
2136v	"	"	1988	C/D	Block	Dull	2-4	(yellowish)	3.20
2466	32¢	Ferry Boat	1995	C	EP	Shiny	2-5		5.00
2468	$1	Seaplane	1990	B	0'all	Dull	1		8.00
2468v	"	"	1993	C/D	EP	Shiny	3		8.00
Flag Issues
2893	(5¢)	"G" Flag SI	1995	Grav.	None	LG	A11111,A21111	(Nonprofit Presort)	1.00
1891	18¢	Flag and lighthouse	1981	B	Block	Shiny	1-7		4.25
1895	20¢	Flag & Supreme Court	1981	B	Block I	Shiny	1-3,5,11, 13,14	(large block)	4.25
1895v	"	"	1981	C	Block II	Shiny	4,6,8-10,12	(small block)	4.25
1895e	"	PC	1984	B	None	Shiny	14		55.00
2115	22¢	Flag & Capitol	1985	B	Block I	Shiny	2,4,6,10, 13-16,21	(large)	3.00
2115v	"	"	1985	C/D	Block II	Shiny	1,3,5,7, 8,11,12 ,17-20,22	(small)	3.00
2115b	"	"	1987	C	SP	Shiny	T1		3.00
2605	23¢	Flag Presort	1991	Grav.	None	LG	Axxx (6)		3.50
2606	23¢	USA I SI	1992	Grav.	None	LG	Axxxx (9)	(ABNC, "23" = 6 mm tall)	4.00
2607	"	II SI	1992	Grav.	None	Shiny	1111	(BEP, letters = 16½ mm)	4.00
2607v	"	II SI	1994	Grav.	None	LG	1111		4.00
2608	"	III SI	1993	Grav.	None	LG	S111	(SVS, letters = 15½ mm)	4.50
2280	25¢	Flag & Yosemite	1988	B	Block I	Shiny	1-3	(large block)	3.25
2280v	"	"	1988	C/D	Block 11	Shiny	4,5, 7-9	(small block)	3.25
2280vv	"	"	1989	C/D	EP	Shiny	1-3,5-11, 13-15		3.50
2888	(25¢)	"G" Flag SI	1995	Grav.	SP	LG	S11111	(1st Class Presort)	4.50
2523	29¢	Flag & Mt. Rushmore I	1991	C/D	EP	Shiny	1-9	(BEP)	4.50
2523A	"	II	1991	Grav.	EP	LG	A11111,A22211	(ABNC)	4.25
2609	29¢	Flag & White House	1992	C/D/F	EP	Shiny	1-16, 18		5.00
2889	(32¢)	"G" I	1995	Grav.	EP	Shiny	1111,2222	(BEP, black "G")	5.00
2890	"	II	1995	Grav.	EP	LG	Axxxx (36)	(ABNC, blue "G")	5.00
2891	"	III	1995	Grav.	EP	Shiny	S11111	(SVS, red "G" perfed)	5.00
2892	"	III	1995	Grav.	EP	Shiny	S2222	(SVS, rouletted)	5.00
2913	32¢	Flag over Porch I	1995	Grav.	SP	LG	xxxxx (5)	(BEP, red date)	5.00
2913v	"	I	1995	Grav.	SP	Shiny	11111	(BEP, red date)	5.00
2914	"	II	1995	Grav.	SP	LG	S11111	(SVS, black date)	5.00
Interested in Flags On Stamps? Collector Bob Hunt has started a study group for that topic - email him at "bh1861@att.net" and tell him you want to join. OR visit his web site to learn more. And don't miss Flags on Stamps by Richard Mallett.
Contingency Issues
2112	(22¢)	"D" Eagle	1985	Grav.	Block	Dull	12		6.00
2279	(25¢)	"E" Earth	1988	Andr.	Block	Dull	1111,1211, 1222,2222		2.50
2518	(29¢)	"F" Flower	1991	Grav.	SP	Shiny	1111,1211,1222, 2211,2222		3.75
(see Flag Issues, above)	(various)	"G" Old Glory	1995
Miscellaneous Issues
2902	(5¢)	Butte SI	1995	Grav.	None	LG	S111	(SVS)	1.00
2905	(10¢)	Auto SI	1995	Grav.	None	LG	S111	(SVS)	1.80
2602	(10¢)	Eagle & Shield I SI	1991	Grav.	None	LG	Axxxxx (42)	(ABNC, "USA" red)	2.60
2603	"	II SI	1993	Grav.	None	Shiny	xxxx (6)	(BEP, "USA" blue)	3.10
2603v	"	II SI	1993	Grav.	SP	Shiny	22221,22222	(BEP, error)	25.00
2603vv	"	II SI	1993	Grav.	None	LG	22222	(BEP)	3.10
2604	"	III SI	1993	Grav.	None	LG	S11111	(SVS, metallic gold)	3.50
2604v	"	III SI	1995	Grav.	None	LG	S22222	(SVS, green fluoresces)	3.50
2908	15¢	Cadillac Tailfin I SI	1995	Grav.	None	LG	11111	(BEP, blue date)	2.25
2909	"	II SI	1995	Grav.	None	LG	S11111	(SVS, black date)	2.25
2149	18¢	Washington	1985	Andr.	Block	LG	1112,3333		3.00
2149a	"	SI	1985	Andr.	None	LG	11121,33333		6.50
2149av	"	SI	1985	Andr.	None	Dull	33333,43444		7.00
2529	19¢	Fishing Boat I	1991	Grav.	SP	LG	Axxxx (4)	(ABNC, jagged "1")	3.00
2529a	"	II	1993	Grav.	SP	LG	Axxxx (7)	(ABNC, smooth "1")	3.50
2529b	"	II	1993	Grav.	None	LG	A5555	(ABNC, smooth "1")	10.50
2529C	"	III	1994	Grav.	SP	LG	S11	(SVS, 1 rope loop)	4.25
2005	20¢	Consumer Education	1982	Cott.	0'all	Dull	1-4		100.00
2150	21.1¢	Letters	1985	Andr.	Block	LG	11111,11121		3.50
2150a	"	SI	1985	Andr.	None	LG	11111,11121		3.75
2281	25¢	Honeybee	1988	(Mix)	Block	Shiny	1,2		3.00
2911	25¢	Juke Box I SI	1995	Grav.	None	LG	111111	(BEP, blue date)	4.00
2912	"	II SI	1995	Grav.	None	LG	S11111	(SVS, black date)	4.00
2525	29¢	Flower (rouletted)	1991	Grav.	SP	Shiny	S1111,S2222		4.25
2526	29¢	Flower (perf I0)	1992	Grav.	SP	Shiny	S2222		4.00
Computer-Vended Postage
CVP31	"	Variable Denomination I	1992	C/D	SP	Dull	1	(BEP)	8.00
CVP31a	"	Variable Denomination I	1992	C/D	EP	Shiny	1		7.50
CVP32	"	Variable Denomination II	1994	Grav.	EP	LG	A11	(ABNC)	5.75
CVP33	"	Variable Denomination III	1996	Grav.	EP	LG	11	BEP	?
Officials
O135	20¢	Official	1983	B	Block	Shiny	1		60.00
O139	(22¢)	"D" Official	1985	B	Block	Shiny	1		70.00

Terms and Abbreviations

Scott No. - Most of the stamps are numbered as listed in the Scott U.S. Specialized Catalogue. In a few cases, I make distinctions that Scott does not, or to which it assigns no unique number or letter, in which case I add "v" (for variety) to the Scott number.

Gum types - I have tried to use the latest terms, sorting gums into three types ? dull, low gloss (LG), and shiny. In most cases, these terms are unambiguous, and you should have no trouble determining the gum type on an individual stamp. A stamp with dull gum, for example, often looks as though it has no gum at all. The gum has no sheen, little or no stickiness, and feels rough. Shiny gum is just that ? very smooth, very shiny (it reflects a bright light source clearly), and sticky to the touch if there is the least moisture on your fingers. Low gloss gum is somewhere between the other two. It feels smooth and has a slight sheen and some stickiness (it will take fingerprints, for example), but it is quite clearly neither dull nor shiny. In a few instances, however,the terms are relative and make sense only when you have seen examples. Of the four recent 32- cent "G" coils, for example, the BEP version (black "G") clearly has shiny gum, and the ABNC version (blue"G") clearly has low gloss gum. The two printed by SVS (red "G") lie somewhere in between low gloss and shiny and even differ slightly from each other. I have called them shiny, but minus the ABNC version, I might have gone with low gloss.

Precancel (PC) - Any overprint added after printing (a practice no longer in use), such as black bars, even if it includes text such as "PRESORTED FIRST CLASS," I have designated a precancel (PC).

Service Inscription (SI) - I have used this term only when the design of the stamp includes some text indicating its intended use (ZIP+4 or Presorted First-Class, for example), and that inscription was printed with the rest of the design.

Presses - Most of these stamps were printed at the Bureau of Engraving and Printing (the BEP), where production equipment and methods have been extensively studied and documented by staff and collectors. The names used are the ones listed in the reference works on my other PNCs page. The presses are as follows:

         Cott. = Cottrell press - single-color intaglio presses (4 of them) at the BEP. The method of printing, with two plates fastened together to form the printing cylinder, created joint lines on the stamps, with a line and plate number every 24 stamps. The last Cottrell was retired in 1985.
         B = B press at BEP, Giori single- station three-color intaglio press with a single seamless printing cylinder, hence no joint lines. Plate numbers occur once every 52 stamps. Dismantled in 1993.
         C = C press at BEP, Goebel single- station three-color intaglio press, single seamless cylinder, plate number every 48 stamps.
         D = D press at BEP, Goebel multi- station combination offset-intaglio press, with an intaglio station identical to that of the C press, hence a plate number every 48 stamps.
         F = F press at BEP, Goebel multi- station combination offset-intaglio press, with an intaglio station identical to that of the C press, hence a plate number every 48 stamps.
         Grav. = generic term, Gravure press, mostly non-BEP, or nothing more specific available
         Andr. = Andreotti multi-station multi- color gravure press at BEP, producing a set of plate numbers (one per color) either every 24 or every 38 stamps.
         (Mix) = more than one press was needed to produce the stamp (BEP)

Tagging - First, a definition:

"Tagging" is the addition of a phosporescent substance, as a coating, or as a part of the paper, to make a stamp visible under the ultraviolet light (UV) used in USPS automated cancelling and sorting machines. It was first used on U.S. stamps on an experimental basis in 1963, and by 1974 was standard on all first-class stamps. Lower value stamps are generally NOT tagged, so that they cannot be used to fool the machines.

I use seven designations for tagging types ? None, O'all, Block, Block I, Block II, SP, and EP. Their meanings are as follows:
1. None: Just that, totally untagged. All precancels are untagged, except by error. Service-inscribed stamps have no tagging, unless they are philatelic issues of stamps issued originally with precancels. Finally, low-value definitives issued since 1990 are untagged, in an effort to prevent their use as a way of underpaying postage.
2. O'all: Overall tagging. This refers to tagging that is applied to the entire surface of the stamp after the design has been printed. It is usually smooth and even in tone and texture, and may obscure the stamp design when activated (under UV light). If you have difficulty recognizing the differences among overall, embedded phosphor (EP),and surface phosphor (SP) tagging, compare known examples of each and develop your own set of rules for differentiating. In most cases, it should not be difficult.
3. Block: This refers to a rectangle of taggant applied last in the printing process on top of the design. It usually is centered on the stamp, leaving an untagged border on all sides. (While the total absence of tagging on a stamp not regularly issued that way may increase its value, variations in the centering of the block tagging do not.) The size of the rectangle varies from one issue to another, however, and sometimes even on the same issue (see Block I and Block II). The block tagging on the 11-cent Railroad Caboose stamp is unusual in that it carries the design of the 20-cent Flag over Supreme Court coil. This came about because the Caboose coil was tagged specially for philatelic sale, using tagging mats that had been used on the other stamp, and had worn down to the shape of its design.
4. Block 1: Larger of two block tagging styles on the same issue. There are four instances, three of them on flag issues, related to the press on which the issue was printed (B or C), since the tagging is applied by a station of the press, more or less as an integral part of the printing process. Of the fourth instance, on the 20-cent Cable Car, which was printed on the C and D presses, I have seen no explanation. I assume the two come from different printings and different tagging mats.
5. Block II: Smaller of the two block tagging styles on the same issue. See Block 1.
6. SP: Surface phosphor is a variety of tagging where the phosphor is added as a last step in the paper-making process, as a coating. It is generally smooth and even, like overall tagging, but usually less bright. Since the taggant is applied before the printing process, and the design is on top of it, it should not interfere with the design when activated.
7. EP: Embedded phosphor is a variety of tagging where the phosphor is actually a part of the coating on the paper (not of the paper itself ? it is not visible from the back). It usually is rather mottled in appearance, which is the chief method of distinguishing it from surface phosphor tagging. Like surface phosphor, it lies under the stamp design.

Printers - From 1894 until the 1980's, almost all U.S. stamps were printed at the Bureau of Printing and Engraving (BEP), the government bureau that prints all our money. In the past 20 years, more and more of the stamp printing has gone to private firms, as the need to economize has forced the USPS to look at other printers. If no printer is stated in the Key Features column, it was the BEP.

         BEP - Bureau of Engraving and Printing
         SVS - Stamp Venturers - a loose partnership of printing companies formed specifically for the purpose of printing stamps for the USPS. The printing company used varies according to the needs of the stamp.
         ABNC - Guilford Gravure for American Bank Note Company

Retail Price - This was the Scott U.S. Specialized Catalog price for the cheapest 5-stamp plate number strip of the item in January of 1996 (scarcer plate number bring higher prices). Some prices are higher now.

The above table was originally published in the September, 1996 issue of The American Philatelist, with whose permission I am reproducing it here. The original title was "Collecting Plate Number Coils".

If you are interested in stamp collecting, and not yet a member of The American Philatelic Society, I recommend you join - my own membership has increased the value and enjoyment of my stamp collecting activities immeasurably. Click on their logo above to visit the main page of their web site and learn more.