I think you can download a chart at printingdigital.net
it was vector artwork, so the file size is not too much & the print size is whatever size you want. It's an array of swatches of varied CMYK values that are noted in the margins, so it is a substitute or an accessory along with a Pantone chart. Pantone may be somewhat of a universal language of color where a client can define a color by fax, phone or email & if you also have a pantone chart, you can look at the color they want... but can you print it, without a lot of trial and error?? If you print this chart, with your common profiles, on your common medias, and your standard speed, quality & resolution settings (which possibly should be printed out on top of the chart)
...then you know that as long as you are using the same inks, media, profiles & settings... you should be able to hit any color on that chart, simply be assigning the same CMYK values.
So, if you match your clients Pantone number with a swatch on your chart, you know you are able to print it.
