Stratasys J850 Manual page 53

A heat-sensitive label is fixed to the UV lamp covers as a warning against
overheating. Its center changes from white to black if the temperature of the
cover reaches 65°C (150°F). If this occurs, do not use the printer, and call
your service provider. As a precaution, it is recommended that you check the
label before and after printing.
The pattern test is the basic verification of the printer's ability to produce
quality models, since it demonstrates the condition of the nozzles in the print
heads. Make sure, therefore, that you perform this test weekly, and whenever
you suspect a printing problem.
1. Make sure that the build tray is empty.
2. Prepare a sheet of pink paper, A-4 or Letter size.
3. In the printer, tape the pink paper to the surface left of the build tray.
4. Press , or open the Options menu and select .