Testing printers
Do not try to print the pictures in this page straight to the printer ! Read the page first !Color scale
Print this page to your printer. As you can see, these is two strips with colours of a rainbow on this pageResolution
One of the oldest and best tests of resolution is the 'Cats Eye' . It is a circle of radial lines drawn with extremely fine pencil. Going inside the circle the space between lines diminishes until either the printer or your eyes can't differentiate one line from another.
Black & White Postscript
It is difficult to produce a figure that can be used with every kind of printer. With Postscript you can allways write a small program to make it. Here a little postscript program psGtest.ps prints 360 lines with linewidth = 0.01. Normal 600 dpi printer cannot make better than linewidth = 0.1, but 0.01 might be seen with better resolution printers.Copy the postscript file ( psGtest.ps ) to your PC and then send it to your Postscript printer. In Windows you can use command ' copy psgtest.ps lpt1: ' In Windows that is connected to a network you can try 'lpr -Sserver -Pqueue psgtest.ps' What you get is this abovementioned circle and in the middle of it you normally have a flover with four leaves 45 deg off horisontal.
Smaller flower - better resolution
I'm not going to the mathematics of the phenomenon, but the shape of the flower
tells the vertical (width of the flower) and horisontal resolution (height of
the flover).
My own Lexmark E312 600 dpi produced a nice symmetric flower of about 20 x 20 mm.
I have added some more material to the test page:
There is three gray scale wedges andone step picture to calibrate the toning.
Do remember, that laser printers don't do real gray tones. They use various
dithering algorithms. Thats why those three wedges.
There is a line frame around the page to show how big your page is and to show that the paper gomes out straight.
There is vertical and horisontal scale. The marks are 0.5 inch apart each other
PS Colour printer test page
psCtest.psThis page might be too hard for some printers. There is again those resolution circles. This time for Red Green and Blue. They are divided to 180 degree 0.5 deg and 1.0 deg segments at 22-158 degree border. This is not an arbitrary angle. I tried to select it so that it doesn't mix with 0, 45 and 90 degree angles who are the worst.
There is a colour wedge for R, G and B plus there is two gray wedges. Another is to be printed with RGB colours and the other with the black. Compare them.
Use the short fife vertical and horizontal colour lines to check the accuracy of the printer color positioning.
Use the line frame to check that the paper goes straight thru the printer. You can use them to check the marginal of the printer too, but that is not the main reason for the frame.
I left the gray circle out of the colour page on purpose. You can allways use the gray page for that.
Last but not least there is my email address. Send me a message, so I'll give you my Bank address so that you can send there some nice sum of money. If you are temporarily out of money, you can allways send me a message to tell how you love this little program.
It seems that the resolution depends not only of the mechanics of th printer
but the drivers too. You will get different pictures by different MSWindows
drivers. Ghostscript gives another kind of picture as well as various Linux
drivers.
The tests found at this page test the printer, not Windows or printer drivers,
because you send the RAW PS CODE to the printer with
lpr
If you are looking for the best resolution, you will have to test, test and
test.
I would appreciate comments to make the pages better. I would appreciate sheets
printed with various printers too.
People here in the University of Turku know where to send them, I hope.
My next dream is to make a comparable test for PCL -printers, so if you have
idea, please contact.
