It took me a while to find this out. If you need to change the default max width of qTip2, here is how.
First set up a new style class.
.my_width_setting_class {
max-width: 1200px;
min-width: 0px;
}
Then in the qtip style attribute, insert our newly created css class.
style: {
classes: 'ui-tooltip-wiki ui-tooltip-light ui-tooltip-shadow my_width_setting_class'
}
That will then override the default settings in jquery.qtip.css.
ref: http://craigsworks.com/projects/qtip2/tutorials/styling/#dimensions