Well that realy depends on what you want to do with the color:
First you need you need to know there are 3 basic color processes for printed work.
1. Spot color = one plate for each color specified
2. 4-color or Process inks
3. 4/c or Process + spot
Spot colors inks are used for jobs requiring less then 3 colors or special inks such as bizcard, letterhead etc or other jobs not containing photographs or pictures which requireing the 4-color process.
If producing a job with photographs or image containing over 3 colors, in most cases is cheaper to produce the job using 4-color inks as pantone spot inks are generally more expensive then process inks. Be aware many Pantone colors are not reproducible using the 4-color process. Which is why we have the third hybrid process or ( 4-color + spot ) , the only problem here is that you are generally limited to 2-3 spot colors as 6+ head presses are rare most.
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Now to answer your question:
First off pantone 877 is a metallic ink, and not reproduceable as 4-color if you convert it to 4-color you will get ruffly ( c47, m 37, y36, k2 ) depending on your separation setup etc?. This will be a flat 4-color gray with a slight blueish cast.
You have added the color to you palette:
Name:
The name field really does not matter, you could call it MyFavColor, The name of the color simply a referance for the RIP to say place all the element colored MyFavColor on the plate or film called MyFavColor. The only important thing to rember is that any graphics created in Illustrator, or duotones or DCS plates in Photoshop referance thecolor using the same exact name.
Model:
You want to select Pantone Coated or Uncoated depending on your paper type the is not really much of a difference. I would choose Uncoated unless you know the paper is gloss coated. Once you Select a model, then switch model you will see the same color covered to the closed value in the new color model.
Spot Color:
If you check this, anything you make with this color will print on a separate plate, If you want to simulate the Pantone color using process ink uncheck this box, Some composite output devices will simulate the pantone colors if spot is check others will simply output a black or gray image.
Halftone:
The specifies the screen angle at which the spot color will be applied if the pantone color is not at 100 %, It asks you to match the angle of one of the standard 4-color angles, This comes into play if you are doing duotones each pantone need to be at a different angle. Or if you are placing a screened pantone over a 4-color image you will choose a color that is least present in the underlying image. I would leave it as it is unless unless you know you need to adjust it, consult you printer.
I hope this explains it,
jstuartj