As a considerable amount of packaging is done in Adobe Illustrator, over the years we've all become used to dragging a little vector version of this symbol to where its needed and at the size required (no less than 3mm). But this can be problematic, especially when text changes or moves to a new position as the symbol has to be moved too.
Far better to simply set it as part of the text, which is a simple affair that has passed a lot of people by. As fonts have been updated to include new characters many now include the estimated 'e'. You can see a list here.
Be careful though, many of these are designed to fit with the font family they are part of and as such aren't technically correct. My advice is to stick with 'Myriad Pro' which gives perfect results.
Now you can move text around, reset it or change colour and the estimated symbol will follow along!