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In a
move reminiscent of laundry soap, International Paper (IP) recently
moved to significantly increase the whiteness of its business and
printing papers.
This follows a trend begun by foreign papermakers
several years ago. Since International is so big, and controls so many
brands, virtually every other North American white paper mill is
following IP’s move.
Let’s briefly look
at some paper characteristics that directly affect books and manuals.
Opacity is the amount of show-through in paper. This
means nothing when printing a poster to hang on a wall, or making a
copy in an office. When printing a book or manual, opacity is very
important, affecting how much the back side of a page shows through to
the front, and one page shows through to another.
The
cheapest and least effective way to reduce showthrough is to increase
paper thickness, usually by increasing weight.
If a 50# paper is too translucent, moving to a 60#
will ever so slightly reduce the showthrough. Of course, it will also
increase the weight and thickness of the book, usually not desirable
characteristics.
A better way to increase opacity is to add mineral
fillers during the papermaking process. If this is done, the paper will
be labeled “opaque.” One of the best known opaque book papers is Cougar
Opaque.
Brightness is the ability of paper to reflect light. Bleaching the paper pulp is a way to achieve brighter paper. Clever marketing has equated higher brightness with better quality, but this isn’t necessarily so.
Whiteness
refers to how neutral the color of the paper is. The trend toward
greater brightness has lead to the addition of more florescent dyes to
paper, which is cheaper than the bleaching process.
Many “white” papers used to have a decidedly yellow
cast. This has fallen from favor as florescent additives give papers a
blue shade, much like great-grandma’s hair. Playing with the shade may
fool the eye regarding brightness, but it can also play havoc with
accurate color printing.
How
does this relate to today’s trend toward ever brighter paper? Here we
straighten out some commonly held myths about paper brightness that can
trip you up if you are not careful.
Brighter is not more opaque. Both brightening and
opacifying add cost to paper. Traditionally, North American paper mills
have added both properties to premium (ie, more expensive) papers, so
many folks have come to assume that brighter paper is automatically
more opaque.
It isn’t, and recently brightened commodity papers
have no corre-sponding increase in opacity. In fact, many of the
high-brightness imported papers that began the trend were notable for
their poor opacity.
Brighter is not
whiter. As mentioned above, florescent additives may make a
paper seem brighter, but play havoc with whiteness. Brightness and
whiteness should be evaluated separately.
Brighter is not higher quality. Higher quality papers
have tradition-ally been brighter, but quality is measured by many,
many factors.
Uncoated papers are now all so bright that whiteness
and brightness are in no way a measure of overall paper quality. This
old “rule of thumb,” never technically accurate, is no longer useful.
Now we
know the facts. Next month we’ll show how
this can help us choose the best paper for the job.
We will also see how the increased brightness of book
papers may present new opportunities for cost savings.
Copresco
president Steve Johnson enjoyed a stint as a judge for College of
DuPage graphic arts GAMUT Student Achievement Awards.
High school and COD graphic arts technology students
competed for awards in digital graphics and imaging, digital
publishing, and press operation categories.
The
critiques and insights the judges provide are valuable learning
experiences for these students.
Steve serves on the college’s graphic arts technology
advisory committee with faculty members, graphic arts industry leaders
and other teachers.
The group provides expertise and input to ensure that the graphic arts program offers relevant course material to meet the needs of organizations that employ the students.
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