Paper Quality

I'm coming into this discussion a bit late so, I'm not sure what has already been mentioned.

You have to be careful with paper weights, if they are done in pounds particularly (as many North American papers are rated). Those unfortunately have little to do with the weight of the paper you are buying in cut sizes like A4 or A3 (or letter size, or legal size, or whathaveyou). Paper weights when given in pounds are determined by the standard printers size the paper is cut to at the mill. They take, I believe 500 pages (which is one ream) and weight it, and that determines the weight of the paper, regardless of how it is cut up later.

That would be fine except the standard paper size for weighing purposes is not consistent. Cover stock, or card stock or bond, all start at different standard sizes, so the weights do not correspond to one another is any logical fashion.

Luckily, specialty papers have gone to using a much more logical system (although it doesn't necessarily correspond to the older "pounds" system). That is using grams (or grammes) per meter (or metre) square,

This is a true "standard, because regardless of the cut size, or size of origin, the weight is based upon one square meter-metre of paper. So, each should be comparable, However, one more caveat. Paper weight does not tell you several other factors which can influence their use:

Opacity - some papers have additives to make them more opaque to reduce "show through" from double-sided printing, while other papers may have high transparency,

Absorbency - This can effect both dot gain, and if the paper is porous enough it may bleed ink right through to the other side

Rigidity - This is how stiff the paper is. Some papers can be thick but floppy, others can be thin but rigid. Again additives and milling process can alter this characteristic. Most papers also have a "grain" which makes them more rigid in one direction than the other

Surfacing - some papers have distinct "sides" to them, which others have equal qualities on both sides

Texturing - the type of surface the paper displays. This may or may not alter how the inks respond.

Thickness - paper weight may not be directly related to thickness. Some coatings weigh more than others, and some papers are weighed with the coatings and some only the base is considered. Kaolin clay is heavy, and a common coating on inkjet papers, for instance.

Shed - some papers tend to flake off the surface with minimal manipulation. With inkjet printing, this can prove disastrous, particularly after the image has been printed.

Surface consistency - some papers simply are milled from a variable pulp and these parts absorb ink differently. That can cause mottling or variation in darkness in otherwise evenly toned areas.

There is no way to know before working with a specific paper how these different characteristics will interact. Papers designated for inkjet use, usually are designed to eliminate these variables, but if you, like myself, use papers not specifically designated for inkjet printing and use them in an inkjet setting, there are bound to be surprises, some pleasant, and some just a bit surprising.

Art

John