First, your underbase doesn’t always have to be white. You can use other colours, even one that’s in the design somewhere else. It all depends on the colour selection for the job.
After white, the most common underbase colour is a grey. For example, a white underbase can sometimes make a red colour like PMS 202 look pinkish. If you use a grey like PMS 428, you may get a better result. But let’s say you have a PMS 109 on the art too. That underbase grey might affect the yellow, so it appears a tad green. A tan underboss could be the answer. This is where your note-taking can pay off as you can create your own reference guide for colours that work for you.
For darker colours you probably don’t need an underbase when printing on coloured shirts. However, that isn’t always the case as the darker the shirt colour, the more of an impact an underbase can have in keeping your Pantone colours true on the final print.
Marshall Atkinson | Atkinson Consulting