Could I tell Inkscape to calculate a large number of Greys, and also a few(3) levels of Color?

I'm taking an Adobe Illustrator in college. My professor is a traditionalist(as well as a print shop owner...) When he saw how well Inkscape can export .SVG; he said the printing cost would be inordinant. He then warned me to not use more than 3 Colors; but when I asked if several levels of Grey would also be an expensive print, he said no!

If I were in Photoshop I would just Trace the Bitmap twice; once with at least 256 levels of grey, and then again with just 3 colors. I could then layer the Color Trace on a Layer over the Greyscale Trace, and set the Color Layer's Mode to Color. But not knowing how to do this with Illustrator(yet...) leaves Inkscape as an alternate, and Photoshop as yet an even later alternative(hence my workflow for the class.)

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Well, Inkscape does have options to trace in grays and colours:

1. Select the imported image (import image by going to file -> import and then location the image)
2. Go to Path -> Trace Bitmap (Shift + Alt + B)

- In the new window, look at the lower section where it says "Multiple scans".
- You might want to select the "Remove background" and "Stack Scans" options (I would suggest have the "Smooth" option unselected)
- You can select the "Grays" option and then modify the amount of scans (I think its 8 by default)... in this case, I guess it would be 256 scans (although I think this would make the file really large and I would suggest using a smaller number like 10, but feel free to experiment)
A new grayscale vector drawing should appear on the canvas now (might take a little time to render, the bottom of the window should display the tracing progress)
- To trace with a few levels of colours, select "Colors" in the Trace Bitmap window, and set the amount of scans to 5 (We use 4 because Inkscape recognizes Black & White as colours, so by having 5 scans, you will get a vector image of 3 colours + black/white). Hit OK and a coloured vector image will show up.

I don't know if this will yield the results you are looking for, but try giving it a shot

Thank you very much for your reply!

Yes, Black is a color.

I'd like to do 256 Greys and 4 Colros; at the same time? When I click between either setting's field the previous fields value is loast; it's forcing me to guage the Greys and Colros with seperate renders?

And is that really what we consider Inkscape as doing, "Rendering?" The Color 256MB processing took only like 5 minutes, and the resulting file was 12MBs; all from my 700Mhz 768MB 'puter. I'm definately going to try 1024 scans next! If this is, actually, a Render process; I'll try to let Inkscape render all night long?

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Cain Brogan wrote: Greys and Colros with seperate renders?

Yes, two renders (two traces, in Inkscape terminology), then layering the colour over the greys.

I'm definately going to try 1024 scans next!

There are only 256 grey levels, so it's not going to do anything useful.

Thanks,

I thought I would have to Trace twice.

Can I do the Laying in Inkscape?

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I'm positive your professor knows more than I do about print (I'm not a professor and I don't own a print business ). And Inkscape is an SVG editor and SVG, in it's current form, is a web standard not a print standard. So your professor would be right raise his/her nose at it.

Having said that, I'm keen to dig more information from you about this problem. My understand is that in the print industry, printing works with spot colours. For the most these spot colours are CMYK (your desktop printer might have a separate cartridge for each of these colours). Highly professional work that require greater colour accuracy might include other discrete spot colours, which requires the printers to have those colours available (usually identified by a unique code). Correct me if I'm wrong here.

SVG doesn't currently support CMYK and definitely doesn't support custom spot colours (i.e. Pantone). SVG uses RGB and it doesn't matter what you do to your drawing you can't escape the fact that each colour (including black/grey) is represented using and RGB value.

So I'm a little confused about what sort of printing you are doing where reducing the number of colours in an SVG somehow makes a difference to the printing process? I would like to know more information about that.

What I would have expect your professor to suggest is to save the SVG as PDF, then open the PDF in Illustrator and change it's colour mode to CMYK. You would then have a print friendly version of your drawing.

Cain Brogan wrote:
Can I do the Laying in Inkscape?

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Yes. Each trace will itself be a layered group, with the number of layers equal to the number of traces. You can separate the layers out by ungrouping each trace.

I envisage you putting the colour trace over the black and white, ungrouping both, then using the raise/lower selection buttons on the toolbar to position the colour layers within the black and white, for a stencil-like effect.

/Later

I had a go myself:

Derived from a flickr image by igorms.

The colour bits looked best on top.

No idea if that's what you're after, nor of the printing issues.