June 22, 2021
Offset printing is a mainstream printing method. The international standard for the dimensions of printing plates it uses has been revised and reissued. The addition of "standard sizes (width and length)" to the international standard is expected to contribute to reducing printing plate stock and waste in supply chains. This should in turn help reduce the environmental burden.
Offset printing is a mainstream printing method. It is based on using printing plates to create printed images (by applying photosensitive materials to aluminum plates), and to reproduce printed materials. However, the printing plates used are produced individually according to the user's specifications. As a result, they already come in some 9,000 different sizes, and this number is increasing. These size differences result in increasing levels of stock and waste in the supply chains, raising an issue that should be addressed. If each printing press uses a different plate size, then a separate stock of plates will be required for each printing press. Accordingly, there is a risk that plates will be discarded as waste if they are not used for a long time.
In order to solve this problem, sizes have been defined as an international standard.
Offset printing is the most common printing method. Ink on a printing plate is first transferred to a blanket (transfer roller), then from the blanket to the sheet.
2. Outline of the standard
ISO 12635,*1 the international standard issued this time, defines the printing plate sizes (width and length) in addition to the already specified plate thickness and flatness, edge straightness, and burr requirements.
When deciding what standard plate sizes to specify, the ISO gathered information on plates from around the world and found that there were many subtle differences in size. To address this, Japan led the revision of the international standard with initiatives that included narrowing down the printing plate sizes to 261 types (approximately 3% of the total number) based on the Japan-developed "Rules for Selecting Standard Sizes." The resulting international standard was issued on June 9, 2021.
Figure 1: Distribution graph of plate sizes, with width and length as the axes (Worldwide)
Four rules for selecting standard sizes
A: Sizes match between plate manufacturers and press manufacturers.
B: Sizes match between two printing plate manufacturers or two press manufacturers.
C: If a press manufacturer's size and a plate manufacturer's size are close (within √2 mm), the press manufacturer's size is selected.
D: If plate manufacturers' sizes are close to each other, the largest one is selected. The same rule applies if press manufacturers' sizes are close to each other.
|X range||Y range||Preferred sizes|
|200-300||300-400||252 x 400|
|200-300||400-500||252 x 400 300 x 463|
|200-300||500-600||274.4 x 574 276 x 578 276 x 582 276 x 597 278 x 575 289 x 600|
|200-300||600-700||289 x 600|
|200-300||1100-1200||No preferred sizes in range|
|300-400||400-500||300 x 463 304 x 483.5 309 x 463 310 x 483 311 x 483 312 x 498 314 x 483 317 x 482 324 x 492 330 x 492 335 x 485 336 x 499|
3. Expected effects
If printing companies, printing press manufacturers, and plate manufacturers cooperate with each other and successfully reduce the number of plate sizes in the offset printing industry in accordance with this international standard, this should help reduce plate stock and waste in supply chains. This can in turn be expected to reduce its environmental burden. From the perspective of the sustainable development goals (SDGs), this is also expected to contribute to more efficient use of resources, the development of new environmentally friendly technologies (Goal 9), and the promotion of resource efficiency to support sustainable production (Goal 12).
ISO12635 Graphic technology — Plates for offset printing — Dimensions
Division in Charge
International Standardization Division, Industrial Science and Technology Policy and Environment Bureau