Color fill. CMYK or RGB

[Abdul Baseer Hai]

Hello All

I am doing a comlpex graphic which has numerous black filled shapes.
some of the fills are not as black as the others. In the fill docker I found that some are filled as CMYK and others as RGB. RGB looks blacker.
I use corel X3.
Which palette should I use and what is the difference. If it is to be RGB, how do I set the program to use RGB by default.
Thanks
Abdul

[Rodne Gold]

What are you using the graphic for? , if its for engraving , you MUST use the default Corel palette and black must be listed as BLACK otherwise it will not engrave properly unless you jump thru hoops and do a colour map change in your driver.
If you are printing and whant a what you see on screen is what you see on print scenario, then CMYK is the way to go as it simulates the colours you will get using that inkset , in fact you need to change colour management settings in corel to simulate professional output to really see what you get.
RGB colours DO NOT translate accurately to printed colours , they are made of emissions of light , whereas inks do NOT emit light but absorb certain wavelengths (to put it simply) and the range of colurs one can get from CMYK is limited compared to RGB (called its colour gamut)

Its pretty easy to change the wrong black to the right black , use the search function in corel and search for all items filled with the wrong black , you will get a selection set and can then fill that selection set (you can group it) with whatever black you want.
If you are using X3 and are tracing an exisiting design , you can set whether the trace will use CMYK or RGB as fills.

[Aaron Koehl]

What are you using the graphic for? , if its for engraving , you MUST use the default Corel palette and black must be listed as BLACK otherwise it will not engrave properly unless you jump thru hoops and do a colour map change in your driver.
If you are printing and whant a what you see on screen is what you see on print scenario, then CMYK is the way to go as it simulates the colours you will get using that inkset , in fact you need to change colour management settings in corel to simulate professional output to really see what you get.
RGB colours DO NOT translate accurately to printed colours , they are made of emissions of light , whereas inks do NOT emit light but absorb certain wavelengths (to put it simply) and the range of colurs one can get from CMYK is limited compared to RGB (called its colour gamut)

Its pretty easy to change the wrong black to the right black , use the search function in corel and search for all items filled with the wrong black , you will get a selection set and can then fill that selection set (you can group it) with whatever black you want.
If you are using X3 and are tracing an exisiting design , you can set whether the trace will use CMYK or RGB as fills.
I echo what Rodne said.

Also, if there are too many versions of "black" in your graphic (lots of dark grays that you want to be black) sometimes you want to search and replace colors within a threshold.

It's pretty to put a CorelScript together to take care of this.

[Abdul Baseer Hai]

Rodne,
I am a little confused.
Let me paint the actual scenario and you give me the best solution.
I use the graphics solely for engraving and therefore do not really care for the CMYK WYSIWYG.
In one job I noticed that the parts which were filled with RGB black were darker than the ones with a CMYK fill so I assumed that RGB is better for me.When I use the corel color bar for the fill, it gives me a CMYK fill and i have to individually go into the color pallette to change it to RGB.
If i understand you correctly, RGB is preferable to CMYK for engraving applications.How do I instruct corel to use RGB as a default fill from the color bar??
Looking at the different color mixes for a CMYK black, it seems that this black is more dark gray than absolute black.

Abdul

[Dave Jones]

I went through this when I first got CorelDraw and it was a struggle, since CMYK seemed to keep comeing back.

Open a new blank file. Start with the color palette on the right. If it's the CMYK one, close it and open the RGB one there. Right click near the top of it and set it as the default palette.

Then in the Object properties palette, on each of the fill and pen tabs, click the color box and select black. Then click the Advanced button and make sure it is using the RGB palette.

Then go to Tools > Options and when that window pops up click on Document. Then check the box for "Save options as defaults for new documents". I can't remember if there are other color options there or not, but go through everything there and make sure they're all set to what you want as your defaults, then click OK.

This won't fix existing documents that have mixed colors. I wish there was a simple "RGB only" button in this program. When in doubt you can click the advanced button in the object properties and it shows which palette that object is using.

Once you have the RGB palette set as the default on the right side you can also select everything in your drawing that has a black fill or a black outline (do one set or the other at a time) and then click or right click the black color in the RGB palette to change them all at once. (click the palette for fills, right click for outlines)

[Rodne Gold]

if you arent using raster (b&w) mode , your driver will see anything thats not black as a colour that will use the default speed and power settings (probably 50/50)

Shades of grey in raster (B&W) mode will be treated differently , ie like you are engraving a photo.
You should not engrave vector type graphics in B&W mode . ALL vector graphics need to use the manaul colour fill mode in your driver , B&W mode is only really useful for jpeg type logos and so forth.
Im not sure why you would worry about the darkness of black on the screen if you were using it for engraving in manual colour fill.

You need to use the Default CMYK palette with all colour managment turned off to for normal type engraving with the GCc machines, when you click on a black filled object , the properties need to list the fill as BLACK . The default CMYK palette is what corel loads with unless you have specified otherwise.

[Dave Jones]

Rodney, I don't know what machine the person who asked the question is using, but with the driver for my Epilog, in the default mode, if you feed it something with a CMYK "black" (which is not truely black) the driver sees it as dark gray and engraves a halftone pattern. If you select RGB black then it sees it as real black and engraves it solid with no halftone pattern. That's the reason for wanting to have RGB blacks instead of CMYK blacks.

[Rodne Gold]

Dave , hes using a laserpro , a GCC machine, doesnt work the same way.

[Abdul Baseer Hai]

Thanks guys.
I now have RGB as default and everything is kosher

Thanks again

Abdul

[Mike Null]

The easy way to change the default color palette is to go to Windows (in CorelDraw) and select palettes then the default that you want. You can show more than one if you like.