Printing Bar Codes (contrast) white ink on Manilla

[nellypope]

I am currently printing bar codes, but wondered if contrast was an issue. Could you print a white bar code on brown cardboard? Or does anyone know where on the t'internet I could find the info?

Many thanks in advance.

[Davethedog]

All super market packaging has Black on White - Remember its only a laser scanner.

[nellypope]

occasionally you get black diaries with white bar codes printed on them. So is this about contrast, I know they can print Black bar codes on manilla, but am concerned that white ink on manilla would not contrast enough for a laser to read!

[ChuckFickens]

errrr, you will have problems printing a white anything on anything.

Your printer has not got white ink!

black on a manila envelope will be fine. for a black diary etc you will have to print it on a white sticker and stick it on.

[MTbowels]

I have seen black barcodes printed on manilla boxes. Granted, most of them are on unit packs eg cereal cases, but it's obviously possible to scan them.

ChuckFickens, as I understand it the colour is immaterial. A printer can make any colour from the colours in the cartridge including white. I've printed in white on coloured paper before now on at least three printers including inkjet models.

The fact that the printer has not got white ink in it makes no difference - if it did, those of us with tricolour magenta/cyan/yellow cartridges would not be able to print in black, green or a myriad of other colours!

[nellypope]

You're Joking REALLY NO WHITE INK!!!!

The packaging is being sent to an outsourced print house, so I am sure they will have "white ink"

Any ideas? It's a contrast issue I am sure, but need to know where I can source this info on the t'internet.

[nellypope]

MT Bowels - Thank you you have confirmed certain Suspicions I think the contrast would be too poor, sorry MT sarky response was not for you ;-)

[ChuckFickens]

MTbowels,

You are incorrect.

You can not make white by mixing other colour inks. to print white you need a white ink cartridge which are only available for expensive commercial printers

Nellypope, if you are sending them to a commercial printers they may be able to print white, best check first though.

[nellypope]

Thanks Chuck!
:-)

[ChuckFickens]

just to clarify a little.

Printers use colour subtraction for making other colours, the primary colours used for this are normally cyan, magenta and yellow. using colour subtraction it is impossible to make white. imagine you had a pot of cyan paint, one of magenta and one of yellow. try and think of what possible way you could mix those paints to make white. it's impossible and if you mix all three you will get black.

Explained why and how here

http://www.ux1.eiu.edu/~cfadd/1160/Ch23RR/Sub. html

the other method of mixing colours is colour addition, this deals with the mixiing of coloured lights. the normal primary colours for this are red, green and blue. with colour addition then if you mix all three coloured lights you get white light.

this should explain colour addition a bit more, and the two little animations right at the bottom show the difference in results of mixing colours using either subtraction (ink) or addition (light)

[ChuckFickens]

oppps

http://home.att.net/~B-P.TRUSCIO/COLOR.htm

[MTbowels]

Sorry ChuckFickens, I don't accept what you're saying. As I said, I've printed in white on a printer that has only a tricolour and black cartridge installed.

[ACtheTROLL]

Chuck right, can't make white

white is an absence of owt else.unless it's an added pigment (not in printers.

As I understand the scanning thing - it is contrast .... as such ... but it's what the laser can "see"

the laser is red ... so you need to think what colours show light and dark in red light

(it's also a problem with milti-coloured mouse mats and laser mouses (mice... meece?).

look at this - red, green and blue light only


http://i36.tinypic.com/2u7r68j.jpg

[ChuckFickens]

Perhaps this will help explain things. You know those little bottles of food colouring you can buy in the supermarket - if you buy one of each of the primary colours that are in your injet printer (cyan, magenta and yellow) Within reason you can combine these to turn white icing into most colours. Use nothing and the icing is still white or use everything and the icing will go a black-brown colour. Use a couple of drops of red and blue and you'll get purple and so on.

But if you start with black icing, there's nothing you can add that will make it anything but black.

It's the same with your inkjet printer - because white is obtained by not having any ink print on the white paper. But of course that only works when the paper is white and you'll get different results on all colours of paper, decreasing as the paper gets darker in colour. Print blue on yellow paper and you should get green printing.

The only way to print in white is to do what commercial printers do - use opaque inks and include a white ink in the process. And as far as I know there's no commercial ink that will do that with an inkjet printer.

Or if you still don't believe me.


http://word.tips.net/Pages/T000848_Printing_in _White.html

http://desktoppub.about.com/cs/printing/f/whit e_ink.htm

[rojash]

"I've printed in white on a printer that has only a tricolour and black cartridge installed"

This is surreal!

Maybe you refilled the black cartridge with Tippex first?

[Lakitu]

^ lol

[MTbowels]

Well seeing some of you consider I'm only fit to be on the receiving end of your wit, it's time I got off this thread.

ChuckFickens, I didn't mean you! Thanks for your help.

[ACtheTROLL]

we seem to be having a little trouble with our bowels...

MTbowels
It's not malicious ... but you were mistaken ... best you can do is take it on the chin ... and laugh while keeping a tight hold of your teddy