Hi All,I am a graphic artist and run an offset press. I have noticed an odd problem that has cropped up thrice in the last 150 odd jobs. When a job is RIP'ed by the service bureau I have sometimes noticed a Patchwork (mesh-like) pattern on the Black separation film. The Service bureau is unable to identify the problem in spite of correcting frequencies. The mesh-like pattern only occurs on the Black separation. C,M and Y are not affected no matter what the density. Upon printing, the mesh effect overlays all other colours. I really need some help on this. The SB takes the easy way out blaming it on the software. Other Service Bureaus also give the same result with varying degrees of density of the mesh. I use Corel Draw 11 and X3 along with Photoshop running on Win XP SP-2 on a system with a Core 2 Duo, Intel 975 Mother board with 2 GB RAM and a 1 GB Graphics card. Can someone out there please HELP!!
Please attach a sample Corel file that has done this or e-mail to davidmilisock@graphictechnology.com
Also can you describe the method used to send th efile to the service bureau? PDF, EPS, PS native CorelDRAW file?
Is the PSD or TIFF perhaps a scanned image, from an already printed picture?Is there anything on top of the PSD or TIFF image, like a lens or something?This looks like a typical moiré pattern problem, and I guess there is a conflict between the image and something else, that makes the RIP create these patterns.
The image is a PSD. I agree that it looks like a moire perhaps, I suspect, caused by incorrect screen angles at seperation. Is trher any way to prevent this happening. Can I prepare the screen angles myself? If so How?
Hi
User defined screen angles can be used from Advanced settings in Separations Menu in the Print Dialog box. Some where in your previous posts, you mentioned that you supply native files to SB. Use of advanced settings is possible if you are preparing the PS file for output. I prefer not to supply native files to my SB. With that almost every thing is under my control.
Digital Dreamz said:Can I prepare the screen angles myself? If so How?
Anand
Dear Anand,
Could yu clue me in on how exactly to prepare an EPS file with correct angle settings so as to eliminate the chance of a Moire. I work in Corel Draw 11 and X3.
Digital Dreamz
Hi DD
As far as my knowledge goes, one does not need to change or specifically set the screen angles for normal CMYK Jobs. The chances of getting moire would be in case you use a scanning of an image which is already printed with dots. I prefer correcting such images in PP. You may need to change the screen angles in case you have used inks from Pantone Pallette (PMS). I don't think there's any kind of setting to make an EPS file from your design. I had mentioned about the .PS or .PRN file of the design. Print dialog box is accessed with CTRL+P. Under separations tab, you can define user specific screen angles and other details once you select Print seperations check box.
Digital Dreamz said:Could yu clue me in on how exactly to prepare an EPS file with correct angle settings so as to eliminate the chance of a Moire. I work in Corel Draw 11 and X3.