Contest Numbers/Letters

In article , Todd Pattist
writes:


Ray Lovinggood wrote:

I learned about the soapy water method after I applied
the letters to the tail. :-(

I applied one side dry too, then learned the soapy wet
method. Fortunately, I started on the trailer's fin :-)
Todd Pattist - "WH" Ventus C

I'll be putting contest numbers on my new to me glider. I've done it before,
but what is the "soapy water method?
Thanks,
Steve