Check list: Did the ink change? Blankets, fountain solution, paper, rollers hardness. Did anything that was documented on your G7 run change? Sometimes vendors change raw materials without alerting the customer.
Try reading the plate screen before printing and make sure it matches your G7 run. Put it on press and measure screen values. Try changing one blanket and measure again. Sometimes there is invisible calcium build up on blankets that can change the dot. Make sure the blankets are cleaned with water every time.
Also check with prepress to make sure they are keeping up with their chemistry, sometimes the dot size may be correct but if the chemistry is in a different state than when you did your G7 run, you may have an issue.
If all of these things check out, it may be possible that you had something go astray in your G7 run. Blankets need to be torqued to the same ft. lbs every time, roller settings, roller temp, dirty grippers, stuck grippers, oscillating rollers on or off, chrome rollers cleaned properly. G7 test runs need to be documented thoroughly and your press has to be in good condition so you can achieve the same product every time. If you do this properly it makes trouble shooting much easier. If any of these items mentioned are changed from your original test run, you need to recalibrate. Something as simple as changing the blanket torque may change your dot size. Make sure you use a torque wrench every time and retorque blankets after a few thousand sheets.
