Sorry, I missed half your question. The difference, is most apparent in the materials used to make the print. From a slide, it is a positive process and requires a different (and expensive...) paper and chemistry (which is also a little more toxic...). The other big difference is the process itself. When you print from a neg, it is the same as a black and white print...the longer the exposure, the darked the print; whereas with a slide/positive process, the longer the exposure, the LIGHTER the print gets...hope this helps.(posted 8899 days ago)