In darkness it is stable for up to three days. The older version of this that created blue paper with white lines was a similar process invented in 1861 and worked like this:įerro-gallate is coated onto a paper from aqueous solution and dried. If you left a page rolled out on the hood of a truck on site in full sun and went home for the weekend, it was not uncommon to come in on Monday morning to a blank page! These things were a pain in the katookus, because exposure to natural or artificial UV light (florescent light bulbs) would cause them to gradually fade. This faded the blue everywhere except where the master was casting a shadow, leaving blue lines behind. You drew your "master" on a piece of vellum or onionskin (or later a sheet of mylar) and then fed the two pieces into the machine, which exposed the chemical on the paper to UV. The paper was turned blue by this coating. The paper was coated with chemicals that included diazonium salt and some other stuff. The diazo process actually produced blue lines on an almost white background. I did it originally without the red background and could not find the triangle on the page. The pic below is the corner of a triangle drawn and solid hatched in color 255 surrounded by a red background and zoomed at 3200% in Adobe Reader X. Don't trust the print preview to show exactly how it will turn out. It will however show up in the print preview as a fairly distinct gray.
It will be so faint though, that you'll not be able to see it. You can set what ever you want to color 255 which is a very pale gray, almost white, but you will get a gray line when it sends to the PDF at the very best. This color would display as white on a black screen, and black on a white screen so you could see what you were doing.Īfter re-reading this I see that the OP is trying to get this to happen in a PDF file.I thought he was trying to send it to a printer. This is a hold over from the old days when you had a black screen or a white one.
If you notice, it lists color 7 as White/Black.
The colors are assigned as follows: 1 Red, 2 Yellow, 3 Green, 4 Cyan, 5 Blue, 6 Magenta, 7 White/Black. Standard color names are available only for colors 1 through 7. Each color is identified by an ACI number, an integer from 1 through 255. ACI colors are the standard colors used in AutoCAD.
0 kommentar(er)
