Color switch when printing renderings

Jim Canale

I have a question about printing windows or layouts that contain 3D objects of multiple colors..

I have found that if I create an object of multiple colors, and one of them is WHITE,  the printout SOMETIMES displays the white as BLACK.   (This seems to be independent of the printer.)   I realize WHITE does not show up on a white piece of paper.   But I can assign a light or intermediate shade of grey, and it still prints out as dark black. 

So I was wondering  if there is any way to control this substitution of colors?

martin@enco.us

I'm not sure there is a 100% solution because not all printers can print "white".  On my system I have color 255 set to Use entity color / Dither on / Conver to grayscale on / Automatic pen / Automatic virtual pen / 0 screening / Use entity linetype / Adaptive adjustment on / 0.0000 mm lineweight / Use entity end style / Use entity join style / Use entity fill style.  Color 255 always prints "white" on the printers I have.  I have read reports that with some printers the best you can get is a very light gray.

Joe Dunfee

 I am not sure I am clear on all aspects of your situation, but I wanted to make sure you were aware that setting an objects color to be white means it will be printed black.  Note that on some color picking screens, white is labeled as white/black, and is color index #7.  This is because some people do drafting with a black screen, and others use a white one. So a white/black colored line will switch colors to be visible on the background chosen.  Obviously, most outputs are on white paper, so the the white/black color defaults to print in black.

Originally colors were often used to deliniate which thickness of pen to use on the pen plotter, and not for actual colors.  The advent of the inkjet plotters meant that this is never the way things are done, though the functionality of doing that is still possible.

In your situation, if you really want the object to be white all the time , consider changing them to color 255, which will always be white.

-Joe

martin@enco.us

Joe,

I would not assume that color 255 will always be white.  With monochrome.ctb color 255 prints black.  With any .ctb that is modified for a particular company any color, including 255, could be redefined.

Jason Bourhill

It looks like you have two options:

1. Assign a true color to your object.
2. Use the standard index color 255, and in your CTB file set that pen color to 'Use entity color', or a true color.

Attach some screen grabs created with solid hatch fill. Using 255 seems more flexible, as it will display in gray if you are using a white background, whereas the true color doesn't change.

If you're working in 3D and printing a rendered view, then Color 7 will render to white for the object faces. However viewpoint, lights, and material settings will play a big part in how it actually prints.


Regards, Jason Bourhill CAD Concepts 

PrintingWhite-02.png

PrintingWhite-01.png

Jason Bourhill

As Martin has pointed out, results will be printer dependant.

Regards, Jason Bourhill CAD Concepts 

Jim Canale

Martin, Joe, and Jason.  So sorry for the long delay in replying to this thread.   I lost the link.   Thank you. 

Joe, I am one of those people who do my drafting on a black field.  

I just created two 3D objects next to each other.  I set the color of one to 250 (black),  and the other to 255 (white).  The print preview for my HP 2600 color laserjet shows the faces of the black object in white and dark grey shades, and the white object in two shades of light and dark grey.

I then switched the color of the "white" object from 255 white to 7 .  The print preview now shows white object in darker shades of grey.  The black object was not changed. 

I then changed the white object to 253 (grey).  THE BLACK OBJECT NO LONGER APPEARS ON THE PRINT PREVIEW!

So I am very confused about this.

Joe Dunfee

 I suspect you are just seeing the results of the faces being at different angles in relation to the light source. 

What is your shade style?  Can you post a screen shot of your objects, both the preview, and the preview?  On the screen shot of the layout before you do the preview, select one of the viewports, so that its properties will show on the right side of the screen.  This way we can see how it is  set to render.

-Joe