Dot gain, referred to as TVI (tone value increase), occurs when the size of
halftone dots on the printed substrate are larger than the halftone dots on the
printing plate. Higher dot gain results in darker, less sharp images; lower dot
gain is inherent in sharp, high quality images.

What causes dot gain?
Every printing process, from offset
litho to rotogravure, has some degree of dot gain, and some of the many causes
include: miscalculations in prepress, over-exposed negative plates, low ink
viscosity and slurred dots on the plate. But often, high dot gain is related to
on-press factors such as:

• Improper pressure (between plates, blankets, rollers).
  
• Improper packing.
  
• Printing blanket surface (too smooth or too rough for substrate).
  
• Ink-carry ability (blanket carries too little or too much).

How can your customers resolve these issues?
Printers can
do several things to minimize dot gain:

• Check for proper packing heights.
  
• Adjust pressure settings.
  
• Make sure the blanket surface is appropriate for the job.
  
• Correct any blanket and roller slippage.
  
• Make sure the press is stable at higher speeds.

An Update
Here is a unique product that has a lot of potential. Chemgon is a patented product that efficiently converts hazardous waste film chemistry into non-hazardous trash. It is legal in all 50 states and is in compliance with all EPA regulations. Please advise your customers that there are some silver recovery companies and hazardous waste haulers that are claiming that Chemgon is not legal in their jurisdictions. This is completely FALSE.
Is Chemgon approved for use in all States?
Chemgon eliminates the hazardous characteristic of photochemical wastes as defined by the Federal EPA, all States and Canada. Once treated, the waste is no more hazardous than a piece of chewing gum and can be disposed in the same method as a non-hazardous piece of chewing gum. Chemgon treated waste is considered a non-hazardous solid waste as defined by the Federal EPA, RCRA rules and regulations. All States (and Canada), EXCEPT California, allow for the use of Chemgon without a permit.
Acquiring a Permit in California
Although the State of California issued a letter in 1997 verifying Chemgon could be used without a treatment permit, the State of California has since advised that a ‘Standardized Permit’ is required to treat photochemical wastes on-site. A permit to treat your photochemical waste with Chemgon can be obtained from your local California CUPA (Certified Unified Program Agency), usually your fire department. A link to find your California CUPA is http://www.calepa.ca.gov/CUPA/CUPAMail.htm. Any updates to the current status will be communicated to our dealer partners.
Why Chemgon?
A full Chemgon container is safe to dispose of with your regular trash. If you choose silver reclamation, evaporation or hauling, you are involved with a lengthy paper trail. The fees for legal disposal and reclamation are quite high. Chemgon provides the small waste generator with an economical option for legal disposal of spent photographic chemicals. You also eliminate the “cradle-to-grave” responsibility associated with hazardous waste disposal.
How do I use Chemgon?
Simply pour equal amounts of fixer and developer into the Chemgon container. It can be filled over time, so staging or other storage is not required. Once full, tighten the lid and place in your regular trash. When the developer and fixer combine in the Chemgon, they react with the proprietary encapsulating, chelating (chemical complexing) and neutralizing polymer. Both developer and fixer must be added to the Chemgon for it to work properly. There is a range of developer to fixer ratios that are acceptable. There can be from 4:1 developer to fixer to 2:1 fixer to developer. Any mixture within this range will become converted into a neutral pH, gel-like substance that can be legally disposed of in a landfill. Remember, the substance must be neutral. (Refer to 40CFR Parts 260 to 299.)
Two different EPA processes are satisfied by Chemgon. They are Treatment of Hazardous Waste and In Process Alteration of Waste. The first happens when you are tray developing or you pour effluent into the container. The second occurs when the overflow or drain valves flow directly into the Chemgon. Technically, the second method never generates hazardous waste because it is treated before it has the opportunity of becoming hazardous.
What are the benefits of using Chemgon?
•
Customers often save 75% compared to hazardous waste collection costs.
•
More convenient than collection or silver recovery; simply fill over time and dispose when full.
•
Reduce potential long-term liability for improper disposal of a hazardous waste.
•
Purchase from your supply partner, eliminate contracts, separate invoices and unnecessary interruptions to your business.
What types of liquid does Chemgon treat?
•
Lith, rapid access, hybrid developer & fixer
•
Mitsubishi Silvermaster activator & stabilizer
•
Photo-typesetting activator & stabilizer
•
Diffusion transfer activator & developer
•
Photographic activator & stabilizer
•
Agfa Supermaster activator & stabilizer

Plus many other photochemical processing-type wastes assuming they are used as directed.

http://www.baypressservices.com/acatalog/Chemgon.html

Measurements in Printing
We
have all looked at rulers used in printing and wondered about some of
the unusual units of measure indicated on the ruler points, picas,
agates and ciceros to name a few.
I hope that you find this interesting and educational.

A
point is a measurement of .0126 or approximately 1/72 or an inch. In
other words there are approximately 72 points to an inch. All type is
designated in points (10-point Caslon, 24-point Baskerville, etc.).
Points are always used to specify the size of type. Typefaces may be set
in sizes from four to 144 points, but are generally used in six to
seventy-two points. Line spacing is
also specified in points (two points of leading, etc.).

Next
is the pica. A pica is used for linear measurements of type (a pica
gauge is a printer’s measuring tool). There are 12 points to 1 pica and
approximately 6 picas to 1 inch. The length of a line is specified in
picas, as well as depth of a type area.
For example, a given block of copy is to be set 20 picas wide by 36 picas deep. Inches are never used in type measurement.

An
agate line is a measure used by newspapers to sell advertising space.
There are 14 agate lines to an inch. An agate line refers to the space
occupied by one line of agate type in one column. The width of the
column can vary from paper to paper. A 60 line ad can take several
forms: 60 agate lines in one column, 30 agate lines in 2 columns, etc.

A
cicero is a continental (European) unit of measurement for type, equal
to 12 Didot points, or .178 inches, roughly comparable to a pica. Named
after the type cast for a 15th century edition of Cicero’s works.

DECIPHERING TYPE SIZES - PICAS AND POINTS FOR MEASURING TYPE AND SETTING TEXT

X-Height is not the average height of all the X-Men
Effective
use of type means knowing how to measure type. Traditionally, type size
is esignated in points and is set to specific pica widths and depth
(column width and height -- 1 point = 013837 in. & 12 points = 1
pica). Two common misconceptions are that 72 points (6 picas) = 1 inch.
(72 points = .996264 inches) and that a letter at 72 points is 1 inch
tall (possible but not
usually true). The letters in the graphic (below) are set at 72 points. The box surrounding the characters is 1 inch high.




.
In the above example, the line that the type sits on is the
baseline. The tail (descender) of the lower case g extends below the
baseline. The tallest character in this specific typeface is the $
(dollar sign). The distance between the top of the tallest character in
this typeface ($) and the bottom of the g is roughly 72 points. As you
can probably tell, none of these characters are
1 inch (or even .996264 in.) tall.

Points
are used not only to measure the type itself, but the space around it.
Setting leading (line spacing) requires a basic understanding of points
and type measurements. Points and picas may also be used to set margins,
specify column widths, and spaces between columns as discussed in
Plunge into Picas.

PLUNGE INTO PICAS - USING POINTS AND PICAS FOR PAGE LAYOUT

Stop inching your way into desktop publishing. The current measurement system of choice for
typesetting
and publication design is picas and points. If your work involves
complex, multi-page designs such as books, magazines, newspapers, or
newsletters, working in picas and points can be a real timesaver. And if
you plan to work in the newspaper or magazine publishing industry,
you'll likely be required to stop thinking in inches or millimeters for
page layout. So why not start now. In fact, you're already half-way
there since if you use type you already work with points.

Newsletter layouts frequently involve small pieces that are difficult to measure in fractions of
inches. Picas and points provide easily for those tiny amounts. Have you heard of the magic of
thirds
in design? Quick, divide an 8.5 inch by 11 inch piece of paper into
thirds horizontally. Now, find 3.66 inches on the ruler.
It's not easy. But 11 inches is 66 picas so each third is 22 picas. Much simpler, but that's just the beginning.
• Points are the smallest unit of measurement. Type and leading are measured in points with 72 points to the inch.
• Use picas for measuring column width and depth, margins, and other larger distances.
• Picas and points have a direct relationship to each other. There are 12 points in a pica.
•
If you're a metric maven you may have a bit more trouble with the
conversion to picas, but for those of us raised on inches it's simpler.
There are 6 picas to an inch. A standard US letter size page is 8.5 by
11 inches or 51 by 66 picas. (6 picas are approximately 25 mm)
• The
letter p is used to designate picas as in 22p or 6p. With 12 points to
the pica, half a pica would be 6 points written as 0p6. 17 points would
be 1p5 (1 pica = 12 pts, plus the leftover 5 pts).
Your software can
take away some of the math for you. For instance, with picas as your
default measurements in PageMaker, if you type 0p28 (28 points) into the
control palette when setting indents or other paragraph settings it
will convert it to 2p4 automatically.
If you're converting existing
designs to pica measurements, you may find it necessary to know the size
of fractions of points (for example 3/32 of an inch converts to 6.75
points or 0p6.75). This chart [offsite link] includes fractions from
1/32 to 1 inch expressed in picas, points, and decimals too.

If you
want to create dummy layouts for a design, remember that depth is
measured in picas. So if you want to know how much vertical space a 48
point headline occupies divide 48 by 12 (12 pts to the pica) to get 4
picas of vertical space.

Link to our Ruler page Measurements in Printing

September 18, 2009

Take Control of Press Production
Quality Control Devices are More Important than Ever
I recently read an article in the PIASC Weekly Update newsletter that is the basis for this Blog entry. In the article, Ken Rizzo, PIA Director of Technical Services, observed that across the industry there still exists a significant lack of process controls for offset printing. Many steps are taken in the pre-press area to assure quality control, but once the job reaches the pressroom, printers are plagued by print quality problems and excessive color variation to the point that effective color management may not be achievable. Here are some areas to help regain control of the pressroom.
Pressroom Color Control.

Solid ink density and tonal value control are key to process control and print quality. Dot gain is often the only point considered here, but it should be remembered that density loss is equally possible and needs to be measured. The fastest method of checking ink density for gain or loss is with a reflective color densitometer. These units can provide information not only on the solid ink density, but also dot gain/loss, tonal value change, density change, ink trap, dot area, hue error, grayness, brightness and other critical variables.

It is also equally important to control the actual color itself. The easiest color check is a visual, comparing colors to known standards from a PANTONE color formula guide. If spot colors are not being used, check the process colors on the color bar to the CMYK in the PANTONE color formula guide. Remember, an out-of-date guide will not yield accurate colors. Always view color under the proper lighting conditions as well.

A quality, properly mixed fountain solution is essential to maintain ink-free non-image areas and maximum color fidelity. Follow the manufacturer’s recommended mixing instructions and then check the pH and conductivity with a properly calibrated meter. One of the most important factors in fountain solution consistency is to mix the concentrate with treated water (distilled, deionized or RO). If the water is inconsistent, the fountain solution will be equally inconsistent. Check the pH and conductivity at the start, middle and end of each shift and log the readings, making notation of any problems being encountered on press.

A clean printing job starts with a clean press. Blankets and rollers need a deep cleaning between jobs to remove residual ink components (pigments as well as the carrier varnishes) from the pores of the rubber. It is obvious that residual pigments will cause color contamination, but residual varnishes that are allowed to dry in the pores will harden the rubber and decrease blanker and roller life. Print quality suffers and customers can be lost. Roller rubber condition can be easily monitored with a Shore A Durometer. Check rollers at least once a week with a durometer. A good two-step roller wash will keep rollers in a “like-new” condition longer and will also help minimize water soluble glaze build-up. A water-miscible wash should be utilized for general blanket and roller cleaning. A flush with plain hot water can’t hurt anything.

Pressures
Pressures should always be set to the minimum to get the job done. Minimum pressures increase plate life, bearing life, roller life and blanket life. Excess pressures cause premature press wear as well as causing unwanted dot gain and uneven solids. It is important to check pressures between ink and water form rollers and plate, plate-to-blanket and blanket and impression cylinder. Check with the press manufacturer for recommended pressure settings. Roller pressures are generally set with ink stripes – the wider the stripe, the greater the pressure. Blanket pressures must be checked on the press. It does no good to measure a blanket thickness off press. When the blanket is tightened on the press, it loses thickness. A quality blanket packing gauge should be used.

The All-Important Paper
All the care and monitoring in the world will not yield a good image if the paper isn’t ready for printing or if it isn’t as specified by the customer. Be certain to test the paper for temperature and moisture content and make sure it has the proper gloss factor as specified by the customer.

Here is a great promortion from Xrite....until September 30, 2009. Purchase an i1XTreme and get 25% off of either an i1iSis or i1iO automated chart reader. http://www.baypressservices.com/acatalog/i1_Specials.html 

Just like any printed piece of literature the image and the colors start to fade after awhile. This can be due to prolonged exposure to sunlight ot bright lights in the shop and some even think that it is due to ozone. Whatever the cause they do fade and your PANTONE FORMULA GUIDE could be incorrect and possibly cost you a re-run if you're the printer that used the old guide to print the new job.

Make sure you have the latest guide especially at the counter where your customer will order and view the job. Make sure all of your sales staff has the most up to date version as well. Remember it only takes a little too much magenta or not enough cyan to totally change the color of the ink...better safe than sorry ! Check out our website for the latest guides and the best pricing.....

http://www.baypressservices.com/acatalog/Pantone_Graphics.html

Continue reading "Pantone Formula Guide"

With the explosion of inkjet printers in the home, the printshop (for signs, banners and proofs) and in the hands of photographers and artists alike the need has never been stronger for accurate color reproductions. It is pretty amazing how well the small home printers reproduce faithful color but as the printers get larger (17", 24" 36" 44" etc) the costs go up as to making prints. It's easy to throw away a 8"5" x 11" print because the color is off but it is pretty painful to throw away 24 " x 30" prints.
Xrite has the i1 spectrophotometer bundled with Profilemaker in a few different flavors. With this bunble you can build and tweek your own ICC profiles and stop wasting paper and ink but more importantly you can take hold of your output and deliver the very best print your printer, ink and paper selection that is capable of.It is an easy bundle to use and now you can profile your entire system from monitor to output device for consistant, accurate results. To find out more follow the link below

http://www.baypressservices.com/acatalog/Xrite_Software.html

This is about the "Bay Area Air Quality Control Board" (San Francisco, CA area). There is talk that new regulations will be in effect starting Jan 2009 requiring printshops in the bay area to reduce their voc's. Then in Jan 2010 the voc's allowed will be reduced again. This new lower voc rule is already in effect in the greater Los Angeles area so we (in the bay area) can benefit from this.

The major solvent manufacturers have already made press washes that will enable you to meet the new requirements. Like all of the Eco friendly solvents of the past there will be (and has to be) some trade offs....that being: now the press person will have to apply a little more "elbow grease" to help the solvents work AND they will have to come back over the blanket and rollers with clean water to flush out the residual chemicals left behind.The new lower voc washes work very well and are ready to go right now. As long as every one realizes the few trade offs involved it will be a painless transistion.

Give us a call to find out more ! 800-660-8656