Diploma and degree certificate photos are generally one inch with a blue background.
All kinds of examination certificates, such as teacher qualification certificate, Putonghua grade certificate, computer certificate and CET-4 and CET-6, require one-inch photos on a white background.
Usually, the specifications of photos are expressed in inches, which is different from the diagonal length of products such as monitors. "A few inches" in the photo refers to the inch length of one side of the photo length. For example, a 6-inch photo is a 6×4-inch photo. There is also a commonly used method to indicate the size of a photo in the world, which is to take the integer value of the short side of the photo and add the letter R to indicate it. For example, a 6-inch photo, the specification is 6×4 inches, which is 4R.
In addition, regardless of the number of pixels in a digital film, we only look at the number of pixels on the long side. 1200 is 5 inches, 1400 is 6 inches, 1700 is 7 inches, and so on ... 1 inch (in inches) =2.54cm.
When we say x inches, we mean the long side of the photo. For example, 5 inches means the photo is 2.54x5= 12.7cm 12 inches means 2.54x 12=30.5cm, and 8x 12 means the long side is 2.54x 12 = 30.5cm, and the short side is 2.54cm..
3R refers to paper, 3R is 89MM, and 5R is 127MM.
Usually 3R means 3*5 is 5 inches, and 5R means 5*7 is 7 inches.