BASIS WEIGHT
When measured in pounds (lbs), basis weight is defined as the fixed weight one ream of paper (equal to 500 sheets) when paper is cut to the
industry standard for that specific grade of paper.
| Paper Type | Basic Size - 500 Sheets |
| Bond | 17"x22" |
| Offset | 25"x38" |
| Cover | 25"x38" |
When measured in grams per square meter (gsm), paper weight is measured in the same way for all different paper types. One square meter is equal to
one A0 sized sheet (3.28ft x 3.28ft) or sixteen A4 sized sheets (8.27" x 11.69"). Therefore, grams per square meter is the weight of 16 A4 size sheets
(or one A0 size sheet) measured in grams.
Conversion from basis weight as measured in lbs to basis weight as measured in gsm:
BRIGHTNESS
Brightness is the percentage of the blue light (at a frequency of 457nm) that is reflected from the paper. The brightness is more a measure of the
quality of the bleaching paper on paper pulp. Brightness is not the same as whiteness (see whiteness definition bellow), and is essential for superior
image quality. The smoothness of the sheet has an influence on brightness - the smoother the surface, the better the brightness.
COATED PAPER
Paper made with a surface coating to one or both sides. Most popular coatings (also called 'finishes') for inkjet papers are
gloss, satin and matte. Coated papers produce sharper, brighter and more vibrant colors and images than uncoated papers.
DPI (dots per inch)
DPI is a measure of the resolution of a printer and describes the number of dots that fit horizontally and vertically into one inch. Generally, the
more dots per inch, the more detail is captured, and the sharper the resulting image.
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GLOSS FINISH
Is a coating on paper which gives the sheet a lighter reflection of light and that results in a shiny appearance. Gloss coatings reduce ink
absorption, which give the sheet an excellent color definition.
GLOSS LEVEL
Gloss level describes the "mirror" - like property of any surface and is defined as the percentage of light that is returned from paper to our eyes,
reflected from the surface at an angle equal to the angle of incidence in comparison with a standard surface. Generally a higher gloss makes the
underlying surface more visible.
MATTE FINISH
Because of this particular coating, the sheet is not shiny like a gloss sheet, but the coating still keeps much of the ink from being absorbed by
paper, which produces an excellent, vibrant color image.
SATIN FINISH
A satin coating is a less shiny coated finish. It has a lower gloss level than gloss finish, yet a higher gloss level than matte finish. Colors and
images are sharp and vivid.
THICKNESS
The measurement of paper thickness is called caliper, which is usually expressed in thousandths of an inch. The higher the caliper, the thicker the
paper.
WHITE PAPER MEASUREMENT L*a*b
'L' - represents lightness/whiteness as determined on a scale of 0 for black and 100 for perfect white (relates to lightness/darkness of the color)
- see whiteness definition below. The "a" and "b" values represent color tints that may be present in paper.
'a' - represents positive for redness and negative for greenness
'b' - represents positive for yellow, negative for blue and zero for gray
Paper that is bluer is perceived in our eyes to be whiter. Paper that is more red or yellow is perceived darker, older, or less white and therefore
less good.
WHITENESS
Whiteness consists of reflected white light, measured on a scale of 0-100, where 0 is black and 100 is perfect white. Typical white papers have
ranges from 80 to 95. Manufacturers will sometimes add chemicals to paper that convert light we cannot see, such as UV, into blue light,
which we can see. In such cases the paper appears whiter and may approach 100.
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