Ive been trying to use embossing powder for lettering, I want to know what paper works best for this and what kind of procedure to follow for this.
Year-old question, but timeless subject matter. You asked about the procedure. For completeness, I'll add a little detail about that, and some thoughts on the paper.
The embossing powder is finely ground plastic that melts at a relatively low temperature. You need to apply the powder to the paper only where you want it. That's done by writing or printing (or stamping) with a very slow-drying ink that's slightly tacky until it dries.
While the ink is still wet, you sprinkle the powder on the paper. It sticks to the ink but not the paper. You shake off the excess powder and you have the writing or printing with a layer of plastic powder stuck to it. When you heat it, the powder melts and forms a shiny raised layer of plastic on top of the ink, and fuses to the paper.
For most writing or printing, you want to be able to see what's on the page before adding the embossing. So the desired ink color is used, then clear embossing powder is added on top. If an exotic color is desired, like gold printing, that color of embossing powder can be used. It's opaque, so you don't see the ink color under it. If you use colored embossing powder and aren't concerned whether the printing is perfect (e.g., rubber stamp artwork), you can even use "clear" ink that's just a tacky medium to hold the powder. For that matter, you can add subtle clear embossed designs by using clear ink and clear powder.
Heavyweight paper works great but isn't required. Any paper is fine if it has a finish that accepts ink well (e.g., slow-drying ink doesn't spread), and is also suitable for a laser printer. Laser printer toner is similar to embossing powder, and is similarly melted and fused to the paper with heat. A wide variety of papers will work, but if you want an easy starting point for paper selection, use paper sold for use in both inkjet and laser printers.