4R

With dimensions of 4 inches wide by 6 inches tall, the classic 4R photo print size has a surface area of 24 square inches and an aspect ratio of 2:3. It is also referred to as the KG size. In the metric system, it is precisely 102mm x 152mm. The 4R name comes from it being approximately 4 by 6 inches when described in imperial units. Compared to other common print sizes, 4R is smaller than 5R, 8R, and 11R but larger than 2R. The origins of 4R date back to the early 20th century when it was introduced as a standard amateur snapshot film size. Its compact rectangular dimensions made it very versatile for capturing both portrait and landscape orientations. Even in today's digital photography world, 4R remains extremely popular for its convenience, quality, and economy as a print size. It can be easily cropped from larger digital images. While larger professional sizes exist, 4R endures as a standard choice for general photo printing needs. Its moderate size also lends itself nicely to framing, album inserts, and collages.