I have started to stamp on silver,  but the sheet is taking on the minor surface details of my metal plate.  I could sand and file the scratches off,  but does anyone have any tricks for minimizing scratches on silver when hammering on a metal plate?   Thanks!

I do a fair amount of forging and that is a problem. The only solution for forging is to have the anvil as polished as the the hammer face. In your case it is a lot easier to polish a two inch square of steel rather then an anvil. If you will work one face of your steel block with wet/dry sand paper until you have gone through 1200 grit and then polish it with the wheel I think that you will not be picking up the texture of the block anymore.

Your metal's going to pick up the surface of whatever you're hammering on. You could place something on top of your bench block (like paper or cardstock) to possibly buffer/cushion it, but then that would change the depth of the textures or stamps that you're hammering with. 

Your best bet is to clean up that bench block. If you're looking to polish your bench block or hammer, we have a tutorial on it here: http://www.artjewelrymag.com/art/Default.aspx?c=a&id=937 

Addie, I did some experimenting with different backings with some scrap silver and stamps, window screen, unbleached muslin, card stock, just to see if it would make an interesting pattern on the back of the stamp. Not such a hot idea except for the window screen, That transferred OK but overall more trouble then it was worth. Nothing like a nicely polished bench block.