Expert: Tom Rouze - 5/17/2006

Question
Hello Tom,
Thank you very much for your helpful reply. Your explanation for the
reason
was as I understood the problem to be and I write to follow-up on your
two points.

Point 1:  I take it that for the black outline, you are referring to
activating the 'stroke'
tool in the the toolbox (and in Windows menu)?

Point 2: In my reading-up on trapping and choking, it was generally
advised
against use with Text. In your usage, are you using separations and
doing
this to selected separations?

Question: Does Clipping Mask have any application with this problem?

Many thanks for your time!
Best wishes,
Raymond
-------------------------
Followup To
Question -
I am using Adobe CS for making promotional brochures that are
professionally printed. The images are created in Photoshop and
imported
into Illustrator. Type is organised with Illustrator and 'Outlined' when
finished. System is Mac with Panther.

I get razor-sharp type if type colour is set to c=0, m=0, y=0 with k set
to any
value depending on shade required and printed on a white
background.
However, if designing for white type on a coloured background the
results are
fuzzy due to the slight mis-registration of colours in even the best
printing.
This also occurs with colour type on any background.

How to achieve consistently sharp results?

With thanks!
Answer -
Hi Raymond,

First the reason for the problem.
When printing with more than one color on top of another you may
have a
slight movement in the alignment of one or more of the colors.  This is
called
registration or trapping.  It's a machine related mechanical problem.  
The
more colors you have will multiply the problem. The less movement
you have
the better the results meaning that you would not see the other colors
peeking into the white area.  This problem exists in every type of
printing.  
Some machines or operators are better than others producing  better
results
but the problem is still there.
Well that's the basic explanation, now for a couple suggestions to help
give
better results.
1. Create a small 100% black outline around the type.  This will help
compensate for the machine movement tolerance.  Usually a small line
won't
be noticed too much.
2. Another thing that prepress people will do in a situation like this is
to find
the weaker colors and choke them back one or two dots. So basically
your
accomplishing the same result as putting a black outline around with a
more
subtle appearance.
The general rule that I have my designers follow is try not to create
type or
thin lines out of more than two ore three colors.  Easier said than done
sometimes but since they are aware of this problem it does help to
design
with this in mind.
An important question to ask your printer what their press trapping
tolerance
is.
The simplest answer to this problem is to choose the strongest color
and
ouline the area that touches a white or light area.
The best answer is to find a printer who should recognize any
problems like
this before it goes to press and then give you some options like I
described.  
Most of the time it just comes down to some additional prepress work.
I hope this helped without too much confusion.  If you have any further
questions please let me know.  

Thank you,

Tom

Answer
Hi Raymond,  Sorry about the delay getting back to you.  Things got busy and didn't have time to get right back.  
Yes, I was talking about stroking the type.  Obviously this is to be used carefully because it will cause letters to fill in and you also don't want the type to look "bloated".  I wouldn't attempt this with 4 pt type and you wouldn't need it with 20 pt type.  Also the amount of colors making up the type plays an important part of making this decision.  Stroking the type is usually only used with reverse or knocked out type.
And yes generally speaking from a design standpoint people advise against using it with text.  However in production it's commonly used to help prevent registration issues.
Now for the clipping mask question.  Hmmm... yes I guess you could attack the problem from this angle but it seems like a longer more involved way to get the same results. And in the process your file will become very large and may have problems ripping.
Another thought I had when I read through your question about getting crisp text.  Depending on the dpi or lpi of the printer this will have a dramatic effect on crispness of type and as I mentioned previously the skill level of the press operator and the tolerances of the press itself.
 
I hope this helped.  If you have any other questions please let me know and I'll be glad to help.

Thank you,

Tom