HP Large Format Color Copiers Integrating your printer in to your existing environment Color Accuracy in a proofing workflow Color reproduction for the HP Large Format Color Copier products family Please download the latest PANTONE tables from the technical support section of: http://www.designjet.hp.com Notes about the document The settings and examples described in this document apply to the HP Large Format Color Copier products family using the latest version of HP Designjet Scan software available at the time of document development. Contents 1. INTRODUCTION TO THE DOCUMENT......................................................................... 4 2. COLOR COPYING GUIDELINES..................................................................................... 5 2.1 CHECKPOINTS BEFORE STARTING A JOB .............................................................................. 5 2.1.1 Scanner ....................................................................................................................... 5 2.1.2 Printer ......................................................................................................................... 6 2.1.3 Touch screen ............................................................................................................... 7 2.2 TOUCH SCREEN SETTINGS DECISIONS .................................................................................. 7 2.3 RUNNING A JOB: OPERATOR SETTINGS............................................................................... 10 2.3.1 Scanning.................................................................................................................... 11 2.3.1.1 Type of original (1.2)......................................................................................... 12 2.3.1.2 Scan resolution (1.4) .......................................................................................... 16 2.3.2 Printing ..................................................................................................................... 17 2.3.2.1 Printer and media profile (2.1 and 2.2) .............................................................. 17 2.3.2.2 Print quality (2.3) ............................................................................................... 18 2.4 POST-JOB RECOMMENDATIONS AND TROUBLESHOOTING.................................................. 19 2.4.1 Post-job recommendations........................................................................................ 19 2.4.2 Troubleshooting ........................................................................................................ 19 2.4.2.1 The colors of the copy are very different from the original............................... 20 2.4.2.2 Grays are wrong in a color copied image .......................................................... 21 2.4.2.3 The copy is not as shiny as the original ............................................................. 21 2.4.2.4 There is a big difference between right and left sides of the copy .................... 21 2.4.2.5 The background results colored when copying newspapers.............................. 21 2.4.2.6 Vertical bands appear in the copy...................................................................... 22 2.4.2.7 A B&W image appears greenish (or pinkish, or bluish).................................... 22 3. ANNEX ................................................................................................................................. 23 3.1 COLOR REPRODUCTION: THEORY OF OPERATION ............................................................... 23 3.1.1 Original..................................................................................................................... 24 3.1.2 Large format scanner................................................................................................ 26 3.1.2.1 Light source ....................................................................................................... 27 3.1.2.2 Paper movement and glass plate ........................................................................ 27 3.1.2.3 Cameras.............................................................................................................. 27 3.1.2.4 Electronics.......................................................................................................... 28 3.1.3 Touch screen ............................................................................................................. 29 3.1.4 Large format printer ................................................................................................. 30 3.1.5 Final image ............................................................................................................... 31 3.1.6 Overall system........................................................................................................... 31 3.1.6.1 Color management ............................................................................................. 31 3.1.6.2 Image enhancement ........................................................................................... 32 3.2 WHICH COLORS CAN BE REPRODUCED? ............................................................................. 34 3.3 GUIDELINES TO CREATE OR VALIDATE A MEDIA PROFILE .................................................. 39 3.4 EFFECTS OF CHANGING DEFAULT MEDIA PROFILE SETTINGS (COLOR)................................ 40 3.4.1 Method ...................................................................................................................... 41 3.4.2 Lightness ................................................................................................................... 41 3.4.3 Saturation.................................................................................................................. 41 3.4.4 Color balance............................................................................................................ 42 3.4.5 Black enhancement ................................................................................................... 45 3.4.6 Background cleaning ................................................................................................ 45 3.4.7 Sharpen ..................................................................................................................... 46 3.4.8 Blur ........................................................................................................................... 46 3.5 EFFECTS OF CHANGING DEFAULT MEDIA PROFILE SETTINGS (B&W) .................................. 47 3.5.1 Method ...................................................................................................................... 48 3.5.2 Lightness ................................................................................................................... 48 3.5.3 Sharpen ..................................................................................................................... 49 3.5.4 Blur ........................................................................................................................... 49 4. GLOSSARY.......................................................................................................................... 50 Notice................................................................................................................................ 52 Color Reproduction for the HP Large Format Color Copier products family. 3/52 1. INTRODUCTION TO THE DOCUMENT The aim of this document is to provide customers with a simple guide to getting good color reproduction when using the HP Large Format Color Copier products. By making the process of scanning and printing easier to understand, we believe users will be able to achieve the desired color reproduction results. This document contains two parts: · The first part provides a set of guidelines, checkpoints, settings and troubleshooting cases that will help the owner of an HP Large Format Color Copier system with the copying experience. The second part (Annex) provides an introduction to color copying concepts, especially those related to the systems under discussion. In addition, the Annex includes: o An assessment of which colors can be reproduced o A set of guidelines to assist the user in creating or validating media profiles o A set of guidelines to the creation of new types of originals · Users who have a good understanding of color copying concepts can use the first part of this document as a practical guide to perform a color reproduction job and as an aid to problem solving. Users who require more detailed information regarding color copying concepts or who seek assistance for advanced configuration of the system should instead refer to the Annex. This document does not include features that are not color related, such as: rotating, scaling, nesting, accounting, paneling, tiling, mirroring and alignment. Nor does it provide details about scanner and printer maintenance (please refer to the other guides for questions related to these features). This document is intended for various HP Large Format Color Copier systems; some settings may not apply to specific products. We hope this document will be useful for you and will help you to succeed in your business. Best regards, HP Designjet printers 4/52 Color Reproduction for the HP Large Format Color Copier products family. 2. COLOR COPYING GUIDELINES The HP Large Format Color Copiers allow an original image to be reproduced using a scanner, a printer and a controller (called touch screen). The reproduction can be done: · · In one step (a Copy process) In two steps (a Scan process followed by a Print process) with an intermediate saving of the digitized data into a file In this document, we will not differentiate between the two cases: we will describe the Scan process and the Print process separately. If you are performing a Copy, please follow both processes sequentially. To reproduce an image accurately, the following steps should be followed: · · · · Checkpoints before starting a job: you should answer these points before starting the job. Touch screen settings decisions: you should take these decisions before setting up the touch screen. Running a job: you should configure the touch screen according to the settings chosen in the previous step. Post-job recommendations and troubleshooting: some points to consider once the job is finished. If the output is not as expected, you can use this part as a guide to troubleshooting. 2.1 Checkpoints before starting a job Before starting a color reproduction job, you should answer the following questions to ensure you are in a correct state to proceed. If any of the answers are negative or uncertain, please follow the recommended actions. 2.1.1 Scanner Is the glass plate clean and free from dust? If not, or not sure, please follow the scanner maintenance manual to clean it. Typically, vertical lines appear in the copy if the glass plate is not clean enough. Is the white background element of the loading mechanism clean? If not, the grays will show a color cast in the copy and the system will behave erratically (some copies will be acceptable whilst some others won't). Color Reproduction for the HP Large Format Color Copier products family. 5/52 Has the scanner been on for more than 1 hour? If not, the colors may vary during the scan. Does the scanner need to run the scanner maintenance process? If so, follow the scanner maintenance manual. If unsure, see section 3.1.2.2 of the Annex. Typically, the scanner maintenance process should be run every 100 scans or once a month, but it depends very much on the type of originals you are scanning. If you suspect that the scanner may have a problem (colors very different from the original, grays not neutral, broken lines), then run the scanner maintenance process. Has the original dried? If the ink is still fresh, the original may be damaged and the glass plate of the scanner may be dirtied. Is the height setting in the loading mechanism adapted to the thickness of the original? If the original is thicker than 2 mm, please follow the guidelines in your scanner's documentation and always remember to handle the original with care. 2.1.2 Printer Is the media properly loaded and with the correct name appearing in the front panel? If not, change the media name or reload the media, otherwise you risk deteriorated image quality. Did you run the printhead alignment and color calibration for the media loaded and the current set of pens? If not, execute a printhead alignment and color calibration as described in section 3.1.4 of the Annex. Is color calibration on? Follow the steps in section 3.1.4 of the Annex. Has the printer been inactive for more than 6 hours? If so, take into account that the first swaths (ink dropping passes) may show a duller color (less ink deliver ...