samedi 21 novembre 2015

Why Don't Printers Print The Same Colors?

Hi Everyone,

Decided to create this thread after reading the build of Airdaves P-47 Lucky. It is a great build thread done by milenio3.

In the thread milenio3 mentions he tried a new type of paper and is not happy with the printed color results. The results are mentioned a few times in the thread by different members.

Dave works very hard to create the correct color for his models. Always experimenting....

His best efforts look different when members do build threads here at PM dot com.

Several things cause these to look different.
1) Type of paper and its Brightness rating
2) How rough the paper is and how it adsorbs the ink (Texture)
3) Converting what is seen on a computer screen (RGB) to CYMK or even sRGB
4) Program used to create PDF
5) Settings used when creating PDF
6) Type of ink (pigment, dye or toner [laser printers])
7) Type of camera used to take the photos. Hi quality lens? Filters used? etc...
8) Lots more factors, but these are the ones we can change the easiest.

Color:
CYMK stands for the ink in our inkjet printers. Cyan, Yellow, Magenta, Black.

RGB stands for Red, Green, Blue (basically-meaning the explanation is rather difficult-to simplify I use the Red, Green, Blue)

One of the best explanations I found for the difference is the following link. It has color illustrations showing the differences:
RGB versus CMYK


Paper / Cardstock:
Many different types of paper. A few types we use for models follow:
1) Bond
2) Copy

3) Vellum
4) Index
5) Cover
6) Tag

The first two are regular printing paper. They might look the same but many differences are available in the two. The last four are types of cardstock, as we already know many differences available here as well.

Texture plays an important in how printed ink looks. Texture effects how the ink is adsorbed, and how it is reflected back to our eyes. Texture is different between manufacturers and their finished paper products.

One common thing they all share and are measured with is a term called "Brightness".

Brightness simple explanation, i.e., All paper is subjected to a test using a specific blue light. The reflection from the paper is measured by a light meter. The reflected "Brightness" is rated with a numbering system. Lower numbers look dull while higher numbers look bright.

Most paper products have a Brightness number somewhere on the package. However, not all manufacturers post it.

When looking at different types of cardstock I have, notice a big difference when laying them side by side.

Brightness rating 86 looks yellow tinted when next to a sheet that is rated 92.

Brightness affects how ink looks on our finished models.

Color conversions between the different ways our printers work also change the way the model will look from one printer to the next.

Lots of factors why our models look different than what the designer intended!

Even if we get a perfect color match, camera used for pictures can change how it looks. This is due to lighting type and quality of camera and lens.

For me, I like checking out build threads to see how everything comes together:

1) Part fit
2) Ease of construction
3) Comments good or bad about instructions
4) Side comments of builders and members reading thread
5) TECHNIQUES everybody builds differently, are there some new tips that can be used
6) Suggestions for improvements
7) Does the finished model look correct

Not to concerned if the "Paint" doesn't quite look right because there are so many different things that can affect the color. If it is close then I'm Happy!

Learned most of this years ago because of a high dollar wide format printer not printing a true black.

No matter what setting used, it will not print black, black. It is more of a greenish tinted black, grays are even more noticeable.

It uses all 6-ink cartridges to create black and it gets really expensive printing SR71 Blackbirds or rocket models that use black.
Did several internet searches, questioned the HP experts and finally found someone who explained that my printer can only print sRGB. Probably explains why the black cartridge lasts the longest!

Please correct me If I've made a mistake on any of the above observations.

Mike


Aucun commentaire:

Enregistrer un commentaire