to white under base or not to?

[Jonas Freeman]

Hello, I mostly print one color jobs. I have a job in which the client is very particular about everything. He has a specific brand he likes (alternative), and has given me specific pms color numbers. I have ordered the custom inks which are basically a copper and particular shade of blue. The shirts and hoodies are black. My concern is weather or not the colors will show up well on the black? Though I am not real familiar with under basing, I have heard something about doing a white under base will help colors to show or contrast better??? Can any one confirm that?
Going to research how to post an image for reference.

[ApeShirt]

Generally speaking, a white under base will make the other colors more vibrant on the black garment. If you didn't get high opacity pms inks then you must have an under base. If you do have HO inks then you should be ok. I know HO blues show pretty well on black.

[Jonas Freeman]

apeshirt, thanks, the inks I got are plastisols from international coatings through Ryonet. The blue is pms 5405c and the copper is pms1395c. Im guessing the Theyre not HO or would say so?? I dont know what the C stands for in the numbers.
So if I am using an under base is it just the an additional copy of the same screen only for white?, or is there a trick to under base, like a bit smaller stencil?? Attached a pic. jpg at bottom, think I did that right?
thanks for the help., Jonas.

[ApeShirt]

If they are opaque inks from Ryonet I believe they will say Ryopaque. The 'C' stands for coated. Coated colors in the pms family have a little sheen to them. You definitely need an under base. Looking at that particular design in the middle, which I assume is the one you are using, it'll require one separate screen for the underbase. You'll want to choke the under base a little. Make the whole image one color and add a 1pt, or similar, outline (different color as the image), around it. Maybe a slightly larger outline if necessary. Then print a transparency of just the fill color and not the outline. This method works for that type of design but not every design. Keep in mind that an outline overlaps the image by half. So if you have a 1" outline on an object then 1/2" will cover the image and 1/2' will sit off the object. I'm exaggerating here with the numbers but it makes it easier to explain, lol.