It all depends on where the "cracks" or "bubbles" are located...I've had great success using paint sticks or the like...paint doesn't need to be glossy, as the glass will make it appear that way...you can't successfully touch up the paint where it comes into contact with any of the nomenclature/labeling or any gold lines, etc...the paint issue can't be too large either...just takes time and patience...good luck!
