Yeah, spot colors are really good when you have your printer/rip dialed to replicate pantone colors accurately. Unfortunately, most of us don't have the skills, resources, or care to make this happen and so we have to make compromises in order to achieve our color goals. Here are a few suggestions for color matching without a calibrated system.
1. Own a pantone color book, either a Formula Guide or Process Color guide so long as it's true to color.
Amazon Pantone Store
2. Print a
pantone color chart with your current rip/printer settings for every material you use. These will be your cross reference from the book to your printer's output. Then simply pick a pantone number on the printed chart that matches your desired color from the book or sample.
3. Convert the spot color to cmyk and then make value adjustments until you find the best match. I usually print a series swatches with graduated values for whatever color I'm after such as C85,M50,Y0,K0...C82,M50....
4. Custom Spot colors (click this
YouTube Video Sometimes you cannot get the desired color using the above method, but you can create custom spot colors that are processed by the rip. In the production manager click on your printer setup/color management tab/"Color Mapping" button. Click the "Add" button and create a unique spot color name like "Hammer Gray" and enter the CMYK values you think would be close. Click OK, and save your preset (upper floppy disk icon), then go back to the Color Mapping button, click on the newly created color and click on the Print Swatch button (Be sure you have media in the printer). It will begin to print an array of colors with your original value in the smack middle. After the print is completed (and laminated if your final product is laminated) search for the best matching swatch and then enter the X,Y location values back into the custom color editor's "Closest matching swatch" fields and then press Update Color, Ok, and save the preset again. Now, in the design software create a new spot color which looks good to you on screen and name it EXACTLY the same way you named your custom spot color. Save your color table View/Color/Save table and there you have it. (Just a note about this custom color setup. It only works in your environment and will not work elsewhere, or in other applications. Best to make a backup of all your rip settings in case you upgrade your system, lose your system, or need to replicate it) I don't advise using this method now that I think about the risks associated with it, but if you have a one time job then this may get you through it.