[comp.lang.postscript] musings

woody@chinacat.Unicom.COM (Woody Baker @ Eagle Signal) (08/20/90)

One other problem with toners.  Most toner is Poly Vinyl Chloride
based (pvc), besides being slightly carcinogenic is it's unfused form,
it is reactive to chemicals.  Freeon, apparently causes it to fuse into
a glassy and extremely fragile form.  Plastics other than MYLAR often
tend to "melt" the toner so that it sticks to them.  You can create a
beautiful gloss using 1 to 2 mil mylar with your image.  I showed this
trick to Don Lancaster, who promptly tagged it at "Bakerizing"...ugggg.

If you place a thin piece of mylar over the toner, and feed it through 
an Omnicrome pressure fuser, or feed it through a copier or the laser, if
you are careful, then peel the mylar off, you will have a smooth glossy
surface on the toner that looks super, and is much more resistant to sticking
to paper.  You can get by with using parchment paper, but sometimes even
that will let the toner flake off.  If you HAVE to put laser printed material i
side of a plastic binder, place a thin sheet of tissue (very translucent, and
high quality) between the cover and the first sheet.  It looks Classy, if 
done right, and will prevent the toner from sticking. 

Recently I encountered a problem in postscript.  I was reading in a buffer
using readline.  sometimes this buffer had a 0x0c in it as a form feed.
I wrote a snippet of code to determine that,

buffer (FF) search  

where ff was substitued by 0x0c (my editor lets me enter anything).
This worked just fine.  It located the ff and executed the routine that
is was supposed to when it found it.  I had occasion to comment the line
out.  Now, comments are supposed to ignore things until the next CR/LF
or newline.  BUT I got a strange error of  -nostringval-  ...Removing
the comment fixed it, replacing the comment  broke it.  Apparently
the comment status got trashed when the 0x0c was found, and search
then tried to do something with invalid data on the stack.  Later
to day, when I was installing the routine and testing it in the target
enviornment (a unix system) I had to edit the file.  I edited it on a
pc, and accidently hit an ESC in a line.  It was after the postcript
code and before the newline.  The code ran until it hit the 0x1B embedded
in the code stream and then flat died.  It took a lot of digging, but
I tracked it down to the 0x1b that was accidently inserted.

the question:
Why do these 2 things happen?  They are neither EOF or newlines?

Cheers
Woody