Inkjet paper specs include weight, thickness, brightness, whiteness, and others to describe the physical characteristics of the media.
In this article, we will concentrate on the ways we describe the thickness and weight of inkjet photo papers.
Need some help feeding thick paper, or adjusting your printer to use thick papers? Read this article on Printer Adjustments for Thick Paper.
Inkjet Paper Weight
The weight of photo paper is the description of the density of the product. While it is correlated with thickness, weight is not necessarily an indicator of how thick a paper will be. That is the reason inkjet paper suppliers publish both the weight and thickness
The inkjet paper industry uses two primary scales to measure and report the weight of paper. Bear in mind that because variations in manufacturing, actual weight can vary plus or minus 5% from the published number.
The metric scale for inkjet paper weight is convenient because it is standardized and applicable around the world. It is expressed in grams per square meter (gsm). A 200gsm paper in the UK is the exact same weight as a 200gsm paper in the USA.
GSM WEIGHT EXAMPLES 120gsm - Light weight 180gsm - Medium weight 260gsm - Standard photo weight 320gsm - Heavy weight
The second weight scale is expressed in pounds. This scale is familiar mainly in the USA. The main concern with the pound weight system is that there are multiple scales within this system. Some of these scales date back hundreds of years. Unfortunately, the only way to relate them is to have a chart on hand and have the knowledge of which scale is being used!
Red River Paper only uses the BOND BASIS pound weight scale. This is because everyone is familiar with a sheet of 20lb. bond paper. We arrive at a bond weight by weighing 500 sheets of 17x22 paper. That weight is the bond weight of a single sheet of paper.
BOND BASIS EXAMPLES 20lb - Copy paper 32lb - Light weight 50lb - Medium weight 68lb - Standard photo weight 86lb - Heavy weight
The thickness of inkjet paper is expressed in mil. One mil is equal to a thousandth of an inch. Because of variations in manufacturing, paper can be plus or minus 1 mil from the published number.
Epson drivers will sometimes use mm when referring to paper thickness. The letters mm stand for millimeter. This use of mm, when mil is the primary convention for paper thickness, is confusing. If you need to convert mm to mil or vice versa, Google will do it via a search. Example - Type "10mil to mm" into the search box for the answer.
THICKNESS EXAMPLES 5mil - Copy paper 8mil - Brochure paper 11mil - Photo paper 14mil - Fine Photo Paper 19mil - Cotton art paper 22mil - Canvas
No article would be complete without examples of the concepts taught!
26lb. ColorJet - Lightweight high quality photo matte paper 5mil / 26lb. / 105gsm
47lb. Premium Matte - Medium weight photo matte paper 8.5mil / 47lb. / 176gsm
68lb. UltraPro Satin - The best selling Red River Paper, ever! 10.4mil / 68lb. / 270gsm
Big Bend Baryta - Fine photo paper similar to wet darkroom media 12mil / 82lb. / 310gsm
Palo Duro Etching - Textured 100% cotton fine photo art paper 21mil / 84lb. / 315gsm
Blanco Matte Canvas - Cotton/poly woven canvas 21mil / 106lb. / 400gsm
For more resources on inkjet paper and more, visit our guide on the different types of paper for printing.