In order to qualify for black & white pricing on the plotter printer (Epson T5270D), your image must first be converted to grayscale. If your image is submitted in color, you will be charged for the color price.
For the best results, you should always work from a duplicate file. Illustrator preserves editing capabilities but to keep yourself organized, it’s in best practice to save a separate grayscale IC print file.
Open file in Illustrator
Select all of the objects whose colors you want to convert.
To select all objects in a file, choose
Select > All. (To deselect all objects, choose Select > Deselect)
Don’t forget to unlock all layers & objects on your artboard!
Object menu > Unlock All
Edit menu > Edit Colors > Convert To Grayscale
NOTE: Use the Edit > Edit Colors > Adjust Colors command to convert objects to grayscale and adjust the shades of gray at the same time.
Your Illustrator file is now ready to save as a PDF file! Happy printing 🙂
For more information, check out
https://helpx.adobe.com/illustrator/using/adjusting-colors.html