How to create white polka dots on coloured paper using Photoshop

Leopardprint

I have just learnt how to create a polka dot pattern using Photoshop. However, I have blue paper and I want to create WHITE polka dots on it. I have tried inserting the pattern on to a transparent and white background and nothing prints. I also tried background colour and it printed black with blue polka dots(same blue as the paper) Is there a step I am missing or is it not possible?

Don't know if this makes a difference but the original pattern was pink polka dots. I used the "create a new filler adjustment layer" and "create clipping mask" to change the pink to white.

Speedwell

You have to have white pigmented ink/toner to print white on colored paper. Additionally you have to tell your printer that "white" does not mean "no print". You have to actually assign a printable color to the white ink. In Photoshop it will look like a color. (At least that's how we had to do it when I worked for a print shop. We usually preferred to use the actual offset printer.)