1、 Envelope code and size specifications

On June 1, 2004, China began to implement a new national envelope standard. The new standard adjusted the types and specifications of envelopes, modified the technical requirements for envelope paper, specified the color of postal code boxes, expanded the artistic pattern area, added information about the sending unit and English reference words for the "stamp area" and "aviation" signs, improved the experimental methods, and supplemented the guiding text content inside the international envelope tongue. The new standard imposes strict regulations and requirements on the wear resistance, smoothness, strength, brightness, and other properties of envelope paper. The specific codes and size specifications are as follows:

⑴. Code and size specifications for Chinese envelopes in China

B6 No.: 176mm × 125mm, consistent with the current envelope No. 3
DL number: 220mm × 110mm, consistent with the current envelope number 5
ZL number: 230mm × 120mm, consistent with the current envelope number 6
C5 size: 229mm × 162mm, consistent with the current envelope size 7
C4 number: 324mm × 229mm, consistent with the current envelope number 9

⑵ International envelope (Western style) code and size specifications

C6: 162mm × 114mm, new international specifications added
B6 No.: 176mm × 125mm, consistent with the current envelope No. 3
DL number: 220mm × 110mm, consistent with the current envelope number 5
ZL number: 230mm × 120mm, consistent with the current envelope number 6
C5 size: 229mm × 162mm, consistent with the current envelope size 7
C4 number: 324mm × 229mm, consistent with the current envelope number 9

Standard size and specification requirements for envelope No. 5 (DL) (Chinese and Western style requirements are consistent)
Finished product size: 220 * 110 millimeters;
Unfolding size (with adhesive port): 235 * 260 millimeters, with a 12 degree opening to produce one;
The margins of the postal code box in the upper left corner are -11 millimeters on the left and -8 millimeters on the top;
The margin of the stamp sticker in the upper right corner is -8mm for the top and -8mm for the right.

Standard size and specification requirements for envelope No. 6 (ZL) (Chinese and Western style requirements are consistent)
Finished product size: 230 * 120 millimeters;
Unfolding size (with adhesive port): 250 * 285 millimeters, with a large opening of 12 to produce one;
The margins of the postal code box in the upper left corner are -12 millimeters on the left and -9 millimeters on the top;
The margin of the stamp sticker in the upper right corner is -8mm for the top and -8mm for the right.

Standard size and specification requirements for envelope No. 7 (C5) (Chinese and Western style requirements are consistent)
Finished product size: 230 * 160 millimeters;
Unfolding size (with adhesive port): 335 * 265 millimeters, with a large opening of 9 to produce one;
The margins of the postal code box in the upper left corner are -25mm on the left and -15mm on the top;
The margin of the stamp sticker in the upper right corner is -8mm for the top and -8mm for the right.

Standard size and specification requirements for envelope number 9 (C4) (Chinese and Western style requirements are consistent)
Finished product size: 324 * 229 millimeters;
Unfolding size (with adhesive port): 370 * 470 millimeters, with a positive angle of 4 open to produce one;
The margins of the postal code box in the upper left corner are -25mm on the left and -15mm on the top;
The margin of the stamp sticker in the upper right corner is -8mm for the top and -8mm for the right.

Note: The above envelope specifications require a size tolerance of 1.5 millimeters. If the tolerance exceeds this size range, the post office will refuse delivery.

2、 Specific content of the national standard for new envelopes

⑴. All envelopes should be horizontal, and the tongue of the envelope should be on the right or top of the front of the envelope. The tongue of international envelopes should be on the top of the front of the envelope.

⑵ For domestic envelopes of B6, DL, and ZL numbers, B grade envelope paper type I and II with a weight of no less than 80 grams per square meter should be used; C5 and C4 domestic envelopes should be made of B grade envelope paper type I and II, with a minimum weight of 100 grams per square meter; International envelopes should use A-grade envelope paper types I and II, with a minimum weight of 100 grams per square meter. The technical requirements for envelope paper should comply with the provisions of QB/T2234 "Envelope Paper", and the reflectivity of the paper should not be lower than 38.0%.

The postal code box in the upper left corner of the front of the envelope is in golden red color, with the color code PAN TONE1795C.

⑷ The upper left corner of the envelope, 90mm to the left and 26mm to the top, is the machine reading scanning area. No patterns or text are allowed to be printed except for the red box.

⑸ The area between the front of the envelope and the right side, 55mm to 160mm away, and below 20mm from the bottom edge, is the barcode printing area and should be kept blank.

Advertisements are not allowed to be printed anywhere on the envelope.

⑺. Art patterns can be printed on the envelope, located in the left area below 26mm from the top of the front, occupying no more than 18% of the front area. Areas beyond the art pattern area should maintain the original color of the envelope paper.

The bottom right corner of the back of the envelope should be printed with the printing unit, quantity, date of manufacture, supervision unit, and supervision certificate number, and the telephone number of the printing unit can also be printed.

3、 Precautions for envelope paper

The four criteria for envelope paper are its printability, apparent characteristics, workability, and ink absorption. At present, Beijing printing factories mainly use 70-150G adhesive paper and kraft paper as envelope printing materials. Due to poor handwriting and ink absorption, it is not recommended to use copperplate paper for printing.