Problems with digital print of sheet music

[Guest]

Hello everyone!

I am going crazy with this issue and really will appreciate any input help I can get.

So this problem occurs only with raster files (vectors are fine) and only with some digital printers (offset is fine). All the sheet music is written by the client in some specialist software and afterwards exported to .jpg/.tif files. On screen everything looks great and the colors are even. Yet after printing, the music examples look "spotty", "wavy", like this:

All the files are 300 dpi, grayscale, .jpg or .tif format and I am making sure that all the blacks are as black as can be . So the problem does not seem to be a result of poor reproduction of halftones (or at least, not only). Is it resulting from a lower screen ruling of digital print (when compared to offset print)? And if so, how do I combat it? Will using a higher resolution files (like 1200 dpi) help?

I can of course just redraw all the music as vectors/ask the client to export .eps files and avoid the problem altogether. But that is not always an option. And, as this is not the first time I encounter this issue, I would really want to understand how the problem appears and how to solve it (if at all possible).

Any advice is greatly appreciated.

[pixxxelschubser]

A solution could be:

you get (vector) pdf from your client.

Maybe a higher resolution could help, but this is IMO a question of the size of your 'music sheet line'. What height does one 'line' have?

Did you tried another printer? Perhaps the minimum line width or the pinter resolution also could cause the issue.

[Guest]

Thanks for all the responses .

As I said, vectors do solve the problem (or rather, do not have that issue). So if a client is able to provide those (whether in pdf, eps, or svg etc.) or is paying me for redrawing the examples, this is non-issue. The problem remains when neither getting vectors nor redrawing the examples is a possibility, and I am stuck with the raster I got. And here I need to understand where the problem comes from exactly, so I can figure out if there is a way to fight it within confines of poor old .jpgs .

For now, I encountered this issue in two separate printing houses. In both cases, when I gave them a file for sample print with music examples in raster, I got the above problem. But when I gave them the same file with music examples in vectors, the print is just fine. So it does not seem to be a problem with the size of the line per se (the line is 0.5 pt).

Sadly, my "musical" client is a University, so simply changing a printing house to a one with better machines is not a possibility either (the printing house that wins the public offer has to be the one used). I tried to acquire a specific information about what machines are exactly used by the problematic printing houses, but it's hard, so I sadly cannot answer that question at this moment (I do not communicate with the printing houses directly in this case but through a university publishing house - I asked about the machines some time ago but got no answer yet). I will try to press for that information if you guys think it can help with understanding.

And as to the size, the sizes of the books vary but stay around B5 (165x235 mm for example). The sizes of the musical examples inside the books are no larger than 131x193 mm.

[Guest]

Oh, and I forgot - on the screen there is no sign of this on 100% zoom (or 200%, or 400% and so on).

[pixxxelschubser · Accepted solution]

Offset printing is fine because these machines has a Rip (Raster Image Processor). The final resolution mostly is 1200 till 2540 dpi and/or does print with a line line raster between 60 till 80 lpi

Some digital printers does not have more than 300 dpi resolution and does often resample your file. And that is much to low for a pure black rasterized lines with 0.5 pt line width.

That's all.

[davescm]

What printer is it that you are using? When you say it is OK on screen, do you see any signs of this on screen at 100% zoom.

Dave

[DaveJCummings]

Exactly, more info on the printer itself would help immensely on troubleshooting this

[DaveJCummings]

Doing it at a higher resolution isn't necessarily going to help. In print, anything over 400 dpi isn't going to show up.  What size is the document you're trying to print up? 

[DaveJCummings]

Also I wonder is if the file is CMYK and if so, if the black is 4 color black or just 100K.  In my day job designing ads,  we're often told to not use 4 color black because with offset printing,  4 color black can cause anomalies when printed .

[Guest]

The images are grayscale. There is not other CMYK component but black and all of it is uniform.

And thank you, pixxxel schubser, you made it clear for me and conclusively answered my question I think. So basically, there is just nothing to be done here without actually remaking the files themselves. So, for curiosity sake, if a raster file in this particular situation (same examples, same lines, same printing machine and so on) had a higher effective resolution (like 600 or even 1200 dpi) - would the results be any different?

[pixxxelschubser]

Sorry, but I think - no.

Try another machine with better physical properties.

[Guest]

Thank you very much for all the help!