I designed a 12 x 12 in. image. I made sure every image/design in the artwork has CMYK settings of 0% CMY and 100% K. However, every time I send the artwork file to my screen printers artwork team, they are getting various values of CMYK colors in the design. I tried sending it as a PDF, PNG, exporting as a bitmap image and their system is telling them I have all these colors in the artwork. I am really not sure what to do as they want to charge me $40.00 to fix this problem. Does inkscape not correctly export CMYK files, I have heard that somewhere but the fix sounded way too complicated for me ..

Any help would be much appreciated ! thanks.

Hi.

I have no experience with cmyk in inkscape but it sounds a grayscale pdf would do the trick.
http://www.inkscapeforum.com/viewtopic.php?f=5&t=16727

And as it can be in cases as easy as clicking an option at printing setup, it migh be a good idea to search for another printer.

I took a look at your link thank you !

I took a different approach however and I did the following. Hopefully this will work. I opened File > Document Properties > Color Management tab > and I selected a profile from the drop down list called 'Generic CMYK profile' ... I then selected that profile and Clicked link profile. I then selected each portion of my image , opened the Fill and Stroke properties, Scrolled over to CMS tab, selected my profile 'CMYK Generic profile' and changed the CMKY values from there. I did this until the entire image had 0 for CMY and 1 for K.

It was strange because the CMYK tab under Fill and Stroke properties already had all CMY levels at 0, but after this new approach and changing the values to zero once again, the black color on the image changed to a different shade of black. Hard to describe but almost as if it was not glossy anymore, more of a flat black.

Will post again to see if the printing company accepts this.

Not sure if that would work.
Anyway, here is a cmyk tutorial by Heathenx:
http://screencasters.heathenx.org/wp-content/videos/ep106/ep106.html

You should be aware of Black and True black, while speaking about cmyk colours.