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 a...

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, export...