Alterations and Commercial patterns are synanomous. Basically you can't get one without the other. I have been working to no end on a customer's blouse pattern from McCalls. Horrible to work with for fullsize women. After the fitting it just makes me want to trash it all and start with a custom pattern. I hate all the slashing and spreading. More paper is used than with designing the pattern. And the time spent in this process is unbelievable.