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Bitmaps or Vector
There are two basic formats for graphic images, vector and bitmap. A bitmap image is made up of
coloured squares called pixels. Most scanners, paint and photo editing programs like Adobe
Photoshop, Corel Photo Paint and Paintshop Pro produce these types of files. Bitmaps are great for
photos and most complex graphics with shadows, fades and 3D effects etc.
Bitmaps need to be prepared in a size (dpi) to suit the intended output. The calculator below will help
you determine scanning resolutions. Bitmap files for large format digital printing are often many
megabytes in size. Adjusting the colour of a bitmap image can be difficult, large files can take a long
time to load and manipulate.
When bitmap files are scaled there is a loss of quality as the scaling program must add or remove
pixels from the image. For correct colour reproduction of large format digital prints we normally
require bitmap images to be in RGB format.
Vector Images consist of lines and curves and are defined with mathematical formula. Vector images
are made up of individual shapes that can be scaled individually or together without any loss of
quality.
Vector files are normally quite small in size the same image can be thousands of times smaller than
its bitmap counterpart. Programs like Adobe Illustrator,
Corel Draw and CAD programs produce vector images. Only vector images can be used for computer
cut vinyl graphics. With a vector image you don't have to worry about dpi.
Preparation Guide
All files should be full scale if possible, if not we can scale the images to suit. If a smaller image
is
sent you can use our dpi calculator to calculate the dpi required. Text should be converted to curves
and PC formatted.
Recommended file formats in order of preference. Vector files: Corel Draw Ver 12, Adobe Illustrator
Ver 9 or .eps (Signlab files are ideal)
Bitmap files: Corel Photo Paint Ver 9, Adobe Photoshop CS, .bmp, tiff, eps or jpg in RGB if possible.
Recommended resolution
Sign Quality - 75dpi. Most suitable for larger images that are viewed from more than one meter.
Standard - 150dpi. Suitable for almost all situations.
Hi Quality - 240dpi. Only when the highest quality output is required, studio quality prints, very small
text, detailed graphics and when viewed at very close distances.
Sending Artwork
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e-mail (files smaller than 5meg)
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CD-ROM
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DVD-R
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100Meg Zip Disk
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3.5" Floppy
Please compress any files you send via e-mail with WinZip. We hope to have our own FTP site in the
near future.
Colour Matching
The colour on your monitor or inkjet printer will almost always be different than your large format
print, however with a little care very close matches are achievable.
Bitmap images are best sent as Adobe RGB (1998) or straight RGB files
If a precise colour match is required we need to have the PMS colours required. It is recommended
that you use a Pantone Process Colour Chart because it is made up of CMYK colours, and will give
a better representation of the final output colours. The Graphics Department can, however, match a
great deal of PMS colours.
Vector images make it easier for us to match colours as we can individually alter the colours of the
individual elements. There is an extra charge for colour matching.
Corel Draw Guide
Signs Plus uses Corel Draw 12 for a large part of our graphics work so there will be less likely to
be
delays or problems in the production of your job if the following guidelines are followed.
Set the page size to the finished size of your job
If applicable bleed images outside the edge of the page
Use PMS colours
Don't use pattern fills or textures for images over 200mm high.
Convert fonts to curves
Adobe Illustrator Guide
Set up page size at the size of the final image required or a direct scale of the final size
Use PMS colours
Convert text to outlines
Save the file as an Illustrator ver 10
Scanning/DPI Guide
Sign Quality - 75dpi
Standard - 150dpi
Hi Quality - 240dpi
To use the calculator below for scanning. Select the output required, enter width of the original, enter
the final width of the image and click on Calculate.
To use the calculator below to calculate the dpi when supplying an image for us to scale. Select the
output required, enter width of the image in your file, enter the final width of the image and click
on
Calculate.
You will find that very large final widths will require larger images than you can scan or supply, just
supply the best file you can and we will resize it using special software (there is an extra charge
for
the service). Remember that an easy way out is to supply a vector file then you don't have to worry
about dpi.
Please Note: Do not scale images up unless you are an experienced Photoshop user or have a special scaling
program like True Fractals or S-Spline. Send the best files you have and we will scale them to suit.
Please do not hesitate to contact us should you require further information or have any problems at
all.
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