David's Screen Printing & Digital Imaging Newsletter - Volume #56

Wed, 13 Oct 1999 16:41:06 +0800

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David's Distributing, Inc.
P.O. Box 324, Glenshaw, PA 15116
412.486.5438 / 412.486.7081 (Fax)

. . . . . . . . . . . . . . . . . DAVID'S . . . . . . . . . . . . . .

Volume #56 . . . . . . . . . September 12th . . . . . . . . . Tuesday

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David's Distributing, Inc. is a supplier to the Screen Printing &
Digital Imaging Industries to include, Graphic, Industrial,
Serigraphic and Textile classifications. We supply
equipment and consumable industry related materials
(inks, films, fabrics, frames, etc). We also offer
FREE technical help relative to materials or equipment
used in the industry. Our advice, based on 35 years
of experience, is offered via phone or e.mail.
To ask a question just send an e.mailto:bettersupply@hotmail.com
and in the subject of the e.mail put the word QUESTION.
You will receive an answer promptly.

We also market inkjet refill kits for most desktop inkjet
printers to save the replacement cost of expensive ink
cartridges. Also, included in this category are Bulk Inks for
Large Format printers such as Encad Novajet, Roland
Camm-Jet and other Piezo Plotters. Inks can be Graphic
Art, Pigmented Outdoor or UV Resistant Artist Archival types.
Specialty inkjet inks such as Sublimation types are also
stocked and offered for Epson Desktop Inkjet Printers.
Sublimation inks are used to transfer images to hard surfaced


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We would certainly like to hear from our readers. We value
your thoughts and we would like to publish your ideas.

To post your comments, questions or opinions to this newsletter,
just send an e.mailto:bettersupply@hotmail.com
In the subject of the e.mail put the word POST

David's Distributing, Inc. makes no warranties, either expressed
or implied, about the truth or accuracy of the contents of this
newsletter, especially when the opinions of others are printed.

..........................Feature Article .............................

Film Positives For Screen Printing
Some Common Misconceptions by Dave Hall

When making photographic screen printing stencils you should
pay close attention to both the image area (A)
as well as the carrier sheet (B).

A. Opaque Images -Type or graphics which block the
transmission of Ultraviolet light.

If you are producing camera or photographic film positives
your images will be of maximum density. It is necessary,
however, to expose the images so that the emulsion side of the
film is right reading (left to right) with the opaque images
on the front or top side of the mylar carrier sheet. This is
true for all film positives. It is exactly the opposite in the
other printing processes such as Offset Lithography. If you
are having your film supplied to you by an outside printer
or graphics house you should specify, always, to have the
emulsion on the top side, right reading.

When you contact a film positive to a direct emulsion coated
or capillary direct film screen you should be contacting the
emulsion side of the film positive to the emulsion on the
screen. If you reverse the positive image you will undercut
your image and the fine details of your stencil will close
and be "not printable". You should not have the carrier
sheet between the two layers of emulsion. With indirect or
transfer type films (exposed off the screen and later adhered
to the mesh) the image side of the film positive should be
against the mylar backing sheet of the film.

All image areas on all film positives must be opaque and/or
they must be able to filter Ultraviolet light. I am referring
to red or amber hand-cut masking films or red photo-exposed
masking films. A specific red or amber color spectrum will
act just as if the image was totally opaque.

Film positives produced with an inkjet printer must have
enough density to be able to block UV light in order to
properly expose an image. Many problems occur when
the image is weak. Some printers are making two copies
and exposing their screens with two positives on top of one
another, in registration, to increase this density . . .
this is not a good practice because you image is not sharp and
clean due to the double layers of carrier sheets. Most desktop
inkjet printers are using dye based inks which do not have the
density of pigment-based inks. David's sells "Pigmented Inks"
for most desktop printers which will produce images about 25%
more dense than standard dye-based inks. You can refill your
current cartridges with Pigmented Inks to increase the density
and eliminate the problems.

B. Carrier Sheets - Mylar, vinyl or vellum.

Mylar is the best carrier sheet for film positives. It allows for
a maximum amount of UV light to pass. This carrier sheet
is as important as the image areas of a film positive. The carrier
must allow for the transmission of UV light to expose your screen
emulsion or film and make it resist the chemical effects of your
particular type of screen ink. Translucent vinyl or paper vellum
filters a portion of the UV light and therefore will cause you to
expose your screen for a longer time to equal the UV output
through Mylar. Not only that, but vellum and vinyl bend the light
rays during exposure causing undercutting and when compared
to camera film positives are not as sharp. Many printers are
successfully using vellum but the difference can only be seen when
the same image is produced on camera film and screens are
made and printed, especially on non-porous surfaces. Vellum
positives are very forgiving when printing on textiles because
of the nature of the printing surface.

Mylar film positives are not only possible on camera but can be
printed with a desktop inkjet printer. David's sells a specially
coated mylar film to hold waterbased inkjet ink in the production
of film positives. The product is called Polyjet Film and the
images printed onto this film are clean and sharp . . .coming very
close to camera positives, especially when using Pigmented Inks.

Next Weeks Topic: Exposure Units / Pro & Con


..........................INTERESTING WEB SITES........................

Currency - Useless Facts - Phones



Here's a nifty little calculator for anyone who uses a credit card
for purchases in a foreign country. It's called the Credit Card Charges
Calculator < http://www.xe.net/ccc/ >, and it will give you an estimate
of the "hidden" charges for these types of transactions -- what the
credit card issuer is adding on for converting the foreign exchange
and processing the transaction. This is part of the Universal Currency
Converters site < http://www.xe.net/map/ >, which has lots of useful
information for anyone doing business with foreign countries. One
page that looks particularly useful is The Export Pricing System <
http://www.xe.net/eps/ >, which helps exporters to negotiate a price
in a foreign customer's currency while confirming the value of funds
to be received in their own currency.

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =


< http://www.uselessknowledge.com/index.shtml >.
I know, I know, this newsletter is called Really USEFUL Sites,
but I couldn't resist adding this site. It has fun facts, quotes,
trivia, quizzes, and a raft of other information that may be useless
to some, but is bound to be useful to others (even if it's only as
a way to kill some time during work).

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =


Finally, here's a site where you can do quick lookups of
telephone area codes. It's the AmeriCom Area Decoder <
http://decoder.AmeriCom.com/ >. You can either type in an area
code and find out what city or state (or Canadian province) it
applies to, or type in the city/state info and find the area
code. You can also look up international codes here.


Windows and Y2K

You may need to adjust Windows (95, 98 and NT) to
ensure that it is Y2K compliant, even if your hardware
has been certified that it is Y2K compliant. I found
it necessary to do so and my machine is only 2 years
old. It is easy to do, as follows:

1. Click on "START"
2. Click on "SETTINGS"
3. Double click on "CONTROL PANEL"
4. Double click on "Regional Settings" (look for the
little world globe icon)
5. Click on "Date" at the top of the page (last tab on
the top right)
6. Where is says "Short date sample", look to see if
it displays a 2 digit year (YY). Unless someone has
previously changed it, the Microsoft default setting
is a 2 digit year. Supposedly, the "Short Date"
format is the date that Windows feeds to all
7. Click on the button to the right of the "Short date
style" and select the format that has the 4 digit year
(mm/dd/yyyy or m/d/yyyy).
8. Click on "Apply" at the bottom right of the screen
9. Click on "OK" to finish the job.
10. Click on the "X" button in the upper right corner
of the "Control Panel" screen to close the window.

Pass this along to your friends.

.............................HOUSEKEEPING ............................

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We value your opinions and thoughts.
If you would like to post your comments or questions . . .

To post your comments, questions or opinions to this newsletter,
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In the subject of the e.mail put the word POST

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that we can all gain from the information. You will be kept
informed about the industry. The greater the participation in
this forum the more we can all learn.

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Thanks for your participation. YHM David Hall