PRINECT Get a lock on colored stock
The best way to accurately reproduce a colored paper stock on a proofing device such as the HP 5000 inkjet proofer available from Heidelberg is to create a new target (press) ICC profile using the PrintOpen module of Prinect Profile Toolbox. First, print test patches for PrintOpen using the colored paper to be reproduced on the proofer. Read the values into PrintOpen using a spectrophotometer, and PrintOpen will create a target profile from this data.
A quicker but less accurate solution is to bring the existing target profile into PrintOpen for editing. Using a spectrophotometer, read the LAB values from the colored paper to be reproduced. Enter the LAB value into the media white point setting in PrintOpen and save the edited profile (under a different name) as the new target profile.