You often hear people talking about how important
DPI is in scrapbooking - You hear people saying - oooooooh thats
got to be 200 DPI or its no good - - What ARE they talking about?
Actually they are talking about PPI
- the correct terminology for the type of graphics we are using
on screen is Pixels Per Inch . DPI or dots per inch refer to the
printing or scanning process only and not to the process of element
creation at all.
Pixels per inch is exactly what the
term sounds like - the number of pixels an image contains per
inch.
Each image is made up of tiny rectangles
- known as a pixel- - the density of those pixels per inch is
known as the PPI.
Here at DSP we create our Elements
to be printed at 200PPI therefore a 12 inch by 12 inch background
will be 2400 pixels across 2400 pixels down.
If we were to tell the printer to
print this image at 8 inches by 8 inches - the pixels would be
shrunk and each inch would now contain 300 pixels ( so you could
say the image is now 300 ppi.)
If we were to tell the printer to
print the image at 2 feet by 2 feet - the pixels would be enlarged
- and each inch would now contain only 150 pixels.
BUT the original image is still 2400
pixels by 2400 pixels. - you see it doesnt matter what the PPI
says - - the image itself still has the same number of pixels.
The quality issues arise when you
take an image and stretch those pixels out too far - so that you
can see each pixel rather than them blending together.
Each image editor is different -
Often they will open an image and the information will say that
the image is a certain number of pixels and the resolution is
72 ppi
this may be the default setting that
this image editor opens all image at. Other image editors open
images at the resolution that the image was created .
It really doesnt matter - it is the
number of pixels contained in the image that is important -
Here is an example
below in figure one is an element
- it is 300 pixels by 300 pixels and my image editor says it is
200 dpi - it says that it is 1.5 inches by 1.5 inches.
fig1
In figure 2 I have placed my element
on a new canvas for my scrapbook page which I have made 12 inches
square at 200ppi
Figure 3 shows another element -
it is also 300 pixels by 300 pixels but the image editor shows
it to be 72ppi
Note also that it says the image
is 4.167 inches
Now I will place this same image
on my canvas
Notice that both images are identical
-!!!!
It is really the number of pixels
contained in an image that is the important factor .
More detailed information about PPI
can be found in our article here
For a printable version of this
quick class, click here
