You'll want to use your new logo in a variety
of sizes - some small, some large. This won't be a problem with
the VECTOR formats we provide you. Since VECTORS are based on
mathematical equations - they can be used at any size. VECTOR
file formats always output at the highest resolution of the device
you're using to print with, so you'll always be assured of the
best reproduction quality available.
RASTER or pixel based images are a different
issue. Because they are created using tightly packed pixels,
these images (.JPG, .TIF,. .GIF) must be in the resolution of
the device that they're being used on. On a monitor that equates
to 72 dpi (pixels or Dots Per Inch), but in print that requirement
balloons to a minimum of 266 dpi. RASTER images should not be
enlarged as the pixels will become visible. Simply changing the
print resolution of a 72 dpi image to a 266 dpi image will NOT
address this problem. To get around this, simply scale your VECTOR
image to the size required, and create a RASTER image from that.
Any form of electronic reproduction (except
for Flash designs and animations) requires RASTER images such
as .GIF and .JPG. Because of the way they're created, RASTER
images lend themselves to special effects more readily. Also,
many office software products utilize RASTER images to import
artwork. You still need RASTER versions of your new logo, but
these should always begin life as your VECTOR image.
Resolution is a measure on how compact you
store the data of an image. Depending if you are going to display
your logo on the screen or if you want to print it, you use different
resolution.
Screen
If you are going to display your logo on the
screen you should always use 72 dpi, unless you want to be able
to resize it.
Printer
In order to determine the resolution for your
logo you need to know which printer you are going to use. To
store your logo in a higher resolution than the printer can print
is pointless.
To scan an image in higher resolution than
300 dpi (Dot Per Inch) is for example in most cases unnecessary
if you are going to print the image on an ordinary laser printer.
The image quality will not improve in printing; it will just
take longer to print.
Images that just contain only black and white
dots should in most cases be scanned in 600 dpi to obtain a good
quality. The exception is if the files become too large to handle,
300 dpi is in most cases acceptable.
The table below displays the file sizes for
uncompressed black & white images in different
resolutions. For more information, see Compression.
| Purpose |
Low Quality
72 dpi |
Mid Quality
300 dpi |
High Quality
600 dpi |
| Images 10*15 cm |
0,02 MB |
0,26 MB |
1,00 MB |
| US-Letter |
0,1 MB |
1,3 MB |
5,2 MB |
Suggested resolution for different media types/printers.
| Media |
Suggested
resolution (dpi) |
| Screen |
72 |
| Laser Printer, 600 dpi |
600 |
| Print |
600 |
Grayscale images are images that contain different
levels of gray to represent photos etc. It is just like a color
photo, just without the color information.
The resolution for grayscale and color images
is set by the printer's resolution. The Line or Halftone
Resolution is a measure on how many rows of groups of dots
a printer can print. A rule of thumb is to use a resolution that
is twice (X2) the Line Resolution.
The table below displays the resolution for
grayscale images.
| Media |
Printer's
Line-resolution
(LPI - Line Per Inch) |
Suggested
resolution (dpi) |
| Screen |
|
72 |
| Laser Printer, 600 dpi |
~60 |
120 |
| Print |
~133 |
266 |
The table below displays
the file size for uncompressed grayscale images in different
resolutions. For more information, see Compression.
To store a grayscale image you usually need 8
bits to save a 256-color image. This is in most cases enough
for a good image quality.
| Purpose |
Low Quality
72 dpi |
Mid Quality
300 dpi |
High Quality
600 dpi |
| Images, 10*15 cm |
0,1 MB |
2,0 MB |
8,1 MB |
| US-Letter |
0,6 MB |
10,4 MB |
41,8 MB |
As you may have noticed, the file size of a
grayscale image is 8 times an black & white image.
A color image is just like a grayscale image
but every dot includes a color value. Since a monitor is using
three colors; red, green and blue,
the images are usually stored in these three colors. This requires
three times as much storage space as a grayscale image.
To get that good quality, color images should
be saved as 24-bit color. This means
16 million combinations that can be shown. Screen shots usually
only require 256 colors. These images only require one third
of the full color image.
The table below displays the file size of uncompressed
24-bit color images in different resolutions. For more information,
see Compression.
Color images for print are rarely scanned with higher resolution
than 200300 dpi, unless you want to resize them.
The table below displays
the suggested resolution for color images. A rule of thumb
is to use a resolution that is twice (X2) the Line Resolution
(LPI). The Line Resolution is a measure on how many rows of groups
of dots a printer can print.
| Media |
Printers
Line-resolution
(LPI - Line Per Inch) |
Suggested
resolution (dpi) |
| Screen |
|
72 |
| Laser Printer, 600 dpi |
~60 |
120 |
| Print |
~133 |
266 |
The table below is displaying
the file sizes for uncompressed grayscale images in different
resolution. For more information, see Compression.
| Purpose |
Low Quality
72 dpi |
Mid Quality
300 dpi |
High Quality
600 dpi |
| Images, 10*15 cm |
0,35 MB |
6,1 MB |
24,4 MB |
| US-Letter |
1,8 MB |
31,4 MB |
125,5 MB |
As you may have noticed, the file size of a
grayscale image is 24 times an black & white image
and 3 times a grayscale image.
If you are working with images on professional
bases and you want to absolutely sure that the colors are perfectly
matched you might want to store your images in CMYK mode.
The CMYK model stores the information as Cyan,
Magenta, Yellow and Black instead of RGB - Red, Green and Blue.
Most professional printers use the CMYK model. If you use the
RBG model which is the most common, the images will automatically
be converted into CMYK mode in the printer process. The
file size for a CMYK image is 1/3 larger than a RBG image.
The basic formula for the file size is for
an image is:
File Size (MB) = (Height
in Inch x Width in Inch x Bit depth x
dpi2) / 8
The reason to divide by 8 is that one byte
is eight bits.
The table below shows the tones for black & white,
grayscale and color images.
| Purpose |
Bits |
Tones |
| Black & White images |
1-bits color |
21 2 tones |
| Color, Grayscale, Index |
8-bits color |
28 256 tones |
| True Color |
24-bits color |
224 16,7 million tones |
| |
32-bits color |
232 4,2 billion tones |
As we discussed the smallest part that can
be displayed is a colored dot, a pixel.
Resolution (dpi) = (No of
Pixels) / (No of Inches)
You can easily see if you want to double the
size in inched the resolution will go down to half.
The relation is very simple. If you want to
reduce the size three times you can scan the image in 1/3 of
the expected resolution.
A 5-inch/cm photo that you want to print in
20 inch/cm on a 200 dpi printer should be scanned in 800 dpi
to compensate the lack of data.
|
Size
|
Millimeters
|
Inches
|
|
US-Letter
|
215.9 x 279.4
|
8.5 x 11
|
|
US-Legal
|
215.9 x 355.6
|
8.5 x 14
|
|
A0
|
841 x 1189
|
33.125 x 46.75
|
|
A1
|
594 x 841
|
23.375 x 33.125
|
|
A2
|
420 x 594
|
16.5 x 23.375
|
|
A3
|
297 x 420
|
11.75 x 16.5
|
|
A4
|
210 x 297
|
8.25 x11.75
|
Corporate
Identity Design 
