I was wondering if all offset printers print CMYK + Pantone ?Or just some models do print Pantine colours? Thanks
All offset printer can use chocolate mousse to pint if you feed it with that... well probably no, but it does not matter what is the color of the ink you feed.
Some Machines can print just one color at the time. That is one head printer. For aditional colors you need to clean the machine and feed the paper again.
Some machines can print 2 colors at the same time. Again if you need a color selection you print for example the cyan and the magenta, wash it, and then print yellow and black. If you are doing a letterhead for a known pizza brand, you use just red and blue.
If the machine can print 4 colors at the same time normally the company does not waste it in printing strange colors, and use it to print color selections, this is a CMYK print, so they do not need to wash it every job. Each head is used again and again with just 1 color. This is not becouse it can not print a spot color, it is for practicity and production times. But if they choose can use it to print 4 metalic colors, or fluorescent ones or whatever... Again it does not matter what you put it. If the cost-benefit is good, they will do that job for you.
There are 5 head printers. They can choose to use it to put perhaphs a varnish after printing the color selections or a spot color. If the varnish needs some modifications it will be only used it for that.
Some 6 head printers can do a CMYK + 2 spot color or 1 spot color and a varnish.
It is not used anymore but there was a 6 ink printing process called hexacrome by pantone, that used CMYK and a green and orange to have wider gamut. It is not used very offen now.
So, all offset print machines can be feeded with cyan, magenta, etc. inks.
But not all machines can print a CMYK work.
If the machine is too small, for example it is only 1 head, and can only print a tabloid or A3 sized paper, it probably does not have the required mechanisms to assure a good registration and uniform ink ammount, so yes, you can change the plate and change the ink, but the quality of the print will be very bad. This kind of machines are used to print cheap 1-2 ink flyers where you do not need a good registration.
In fact, the issue you could face is that a lot of small printers only print in Pantones and not in CMYK because they have 1-2 color small presses.
In other words, their presses can only have 1-2 plates for each pass. In that case, they will do a good job in Pantone but really not in CMYK process because the CMYK separations might not be well aligned since they're not printed at the same time.
Usually a printer that prints in CMYK will print any Pantone as well, unless your are using an online printer or getting some economical process printing by having your project printed at the same time as other projects.
By default, you can assume that a printer who does CMYK printing can use at least 4 different Pantones for each pass. But you can get more if you need it; either the printer will do extra pass (eg. print again the sheets with the extra Pantones) or simply use a press that can use more plates!