Black Album

I've always wondering about the actual cover. I remember I got the cassette for christmas the year it came out - the metallica logo and the snake were barely visible. I remember the metallica logo looked really faded like if someone tried to erase it. Was this the original concept for the album art? I have seen later releases of the album and the metallica logo is much more vibrant and clear.

I know it is known as the black album but why so many different varients?