RISO
FILE PREP
GUIDELINES
printfx
POSSIBLE SOLUTIONS
GRAIN-TOUCH
Diffusion Dither Image: creates a random dither pattern.
(Preferable
for illustration unless you want the half-tone
dots look). On
ce Grain-Touch option is selected, there
are no
Screen Frequency/Angle settings available.
SCREEN-COVERED
Bitmapped Image: creates half-tone dotted patterns.
SCREEN FREQUENCY
Control the size of the dots produced.
Higher numbers = Smaller & more dots
Suggested Screen Frequency numbers: 75, 80, 85
(Try to don’t go higher than 90)
SCREEN ANGLE
Control the angle that the pattern is set to in order to
avoid moiré effect. For one color work, a typical
angle is
45°. For two colors work, You will put 30°
angles apart from each other
15°, 45° (Usually the
lighter colors get the lower angles). For CMYK printing:
Yellow:0° Pink:75° Blue:15° Black:45°
COLOR OPACITY
Keep the color opacity between 80% - 90% (Never 100%).
When you have a large flat area of 100% ink coverage,
the paper would probably get stuck to the drum.
INTERVAL PRINTING
Slow down the printing speed by using Interval Printing.
This may avoid ink transfer from heavily inked areas
on to the back of the next sheet.
Please refer to our Riso ordering form for pricing.
$
PRICING
A PrintFX staff member must be present when using
the
Riso printer. Students may NOT load paper into
the machine, change ink drums, or touch the internal
components
of the Riso printer.
POLICIES & PROCEDURES
PHOTOSHOP FILE PREP
Photoshop
separates out each color channel or layer
into individual grayscale PDF files:
Make your image CMYK
Image > Mode > CMYK Color
Split your image into separate color channels
Channel Window > Split Channels
Adjust brightness and contrast for each color channel
Image > Adjustments > Levels or (Brightness
and Contrast)
Save each color channel to PDF file format
File > Save as > Photoshop PDF (High Quality Print) >
Option (Do Not Downsample) > Compression (None)
Make your layers to PDF files format
File > Export > Layers to Files > Select PDF >
Encoding (Zip)
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Alternatively, if you have prepared your color
separations in layers instead of channels,
you can convert them to grayscale and use
the “Layers to Files” function to split them
into individual PDFs.
TIPS
ILLUSTRATOR FILE PREP
Illustrator separates out each layer into individual
grayscale PDF files:
Save each color layer to PDF file format
File > Save as > Adobe PDF (High Quality Print) >
Compression (Do Not Downsample) > Compression (None)
Adjust brightness and contrast for each color channel
Edit > Edit Colors > Adjust Color Balance
Updated SEP. 2021
Monday - Friday 9 am - 6 pm
Pomerantz Center 5th Floor D529A
212 217.5470 | www.f itnyc.edu/printfx
HOURS OF OPERATION
Duo color images are created by layering one color
over another. This is a duotone image printed using
Blue and Pink.
Riso printing is like digital screen printing, you print one
color at a time. Each color requires a separate screen
”Master" (Riso printing language) to produce a single
color print. The Riso printer uses environmentally friendly
soy oil or rice bran liquid based emulsion ink. It is
semi-transparent, providing the opportunity to use a
layering technique to produce multi-colored prints.
RISO PRINTER
The Riso printer cannot print full bleed to the size of
the paper. The maximum printable area is 10”x16”
on11”x17” paper.
We don’t use coated paper because smooth and glossy
surfaces don’t work well with Riso ink.
PRINT AREA & PAPER TYPE
Typically the most prominent color or darker color printed
first and the lighter color printed last, but the order can
be switched to achieve a different effect. If you want a
specific color to be more prominent, that color should
be printed first, because the first color soaks into the
paper and the overlay color loses vibrancy when printed
on top of the other ink.
The Riso printer uses inked drums to create the image.
It takes a minimum of 15-30 prints to fully ink up the
drum and print correctly.
Riso uses Rice oil (Soy oil) based ink with no drying agent.
Ink dries purely form absorption to the paper. When you
are printing more than 2 colors, the recommended wait
time to print the 3rd/4th color will be about 4-8 hours,
preferably one day downtime. If the print has a lot of
heavy ink coverage or dark colors, preferably wait for
2-3 days.
INK & DRYING TIME
Single Color = 1 file (Monotone)
Duo Colors = 2 files (Duotone)
Your artwork should be separated into individual grayscale
pdf files (300dpi) for each color that is to be printed.
You can print two colors at a time and up to four colors.
PRINTING
Trapping
Example
Mis-registration
Example
Registration is fairly accurate with two color artwork.
Printing more than two colors will require more than one
pass, and it’s best to assume that misregistration will likely
occur. Include trapping where necessary. It is difficult to
line up your artwork perfectly, so bear this in mind in the
designing process.
REGISTRATION
Overprinting
Example
Knockout
Example
Overprinting is when colors are printed over each other.
This creates new blended colors. Knockout is when you
cut out overlapping colors from the lower layers so that
you only print with the pure spot colors.
OVERPRINTING VS KNOCKOUT
The Riso printer feeds in paper using a set of rubber
rollers. If there is a lot of ink on the page, be aware it
might be transferred onto the rollers leaving unwanted
track marks on your next print (pass).
Try to avoid printing in the center of the page until the
end, to avoid excessive roller marks. Also, give some
drying time and ask the lab technician to clean the
roller if necessary.
Roller Marks Example
ROLLER MARKS
Pink Duotone ImageBlue
Photo by Charles on Unsplash
