There's some obvious solutions -- ya know, like cleaning the pasta machine. There's also work-arounds, like running a baby wipe or some scrap clay through the machine first. But what if, despite your best efforts, you still get streaked clay?
Last week, Victoria James of Victoria James Art posted a solution to this problem on the Polymer_Clay_People Yahoo! group. Turns out that since those streaks are just on the surface, they wipe right off. Pour some rubbing alcohol onto a paper towel or baby wipe and just rub the streaks off the raw clay... Easy as that!
Thanks for the great tip, Victoria. Maybe now I can take "cleaning the pasta machine" off my list of things to do this year!