our silver stain procedure is a little different than yours (we use a method modified from that of merrill, et al).
however, if you add a crystal (small to medium) of sodium thiosulfate to your developer then your background should remain translucent. also, we wash 2x with 1/3 of the developer before developing with the final 1/3. we stop development with 1% acetic acid (actually, we usually use our coomassie destaining solution (30% methanol, 7% acetic acid) so that the gel shrinks back to normal) after removing the developer and washing with water a couple of times (to remove thiosulfate, it doesn't like acid).
careful with the water washes after silver incorporation. too much washing will remove too much silver (it is not bound tightly to the protein).
i almost forgot, make sure sds removal is as complete as possible, it binds silver like crazy and creates very strong background.
Edited by mdfenko, 28 November 2013 - 01:24 PM.