The comments preceded by ">" are John, "[]" are Bill andmy own comments are preceded by "--" I've pruned many original quotations from the paper to leave only the relevant bits. In several places you've suggested offsetting defined terms in quotation marks. These terms will all be in italics in the final copy.

"Most of the images were produced outside of the reproduction
environment; that is, we had no access to the image as viewed in its
original form".
>
> "reproduction environment" - I think "design environment" would be better
> here - what we're doing is reproduction!
-- which is why our environment is a reproduction environment. The point is that we didn't make the images.
NEW: Most of the images printed were designed outside of our environment; that is, we had no access to the image as viewed in its original form


"The reproduction system used is calibrated using CIE tristimulus values."
>
> "reproduction system" -> "output devices" ? On the grounds that "reproduction"
> is a process that makes use of various devices?
-- I want to emphasise the system rather than particular devices, so I'd rather not change it.


"Why is this so, and what can be done to improve the situation? The answer to this question is the crux of cross-rendering, ... Yet it is solvable, since image reproduction is routinely done in the graphic arts business".
>
> I suggest "Why this is so, and what can be done to improved the situation,
> is the crux ``cross-rendering,'' the difficult ..." This is a little
> more formal. The quotes around ``cross-rendering'' are suggest that we
> are defining the term.
>
> Do we want to weaken "solvable" to something like "more-or-less solvable" ?
> The National Gallery doesn't believe it's a solved problem!
[Weakening solvable seems good. I suggest something like "Yet, in many
applications it is solvable, since ..."]

NEW: Why is this so, and what can be done to improve the situation is the crux of cross-rendering, the difficult problem ... Yet, in many applications it is solvable, since ...
-- cross-rendering will be in italics


 "Making this knowledge explicit has two benefits: graphic arts practice can benefit from a controlled scientific treatment, and automatic or semi-automatic production of images under computer control becomes possible".

[I suggest rewording: There are at least two reasons for making this knowledge
explicit: graphic arts practice will benefit from a controlled scientific
treatment, and automatic or semi-automatic production of images under computer
control will become possible.]

NEW: There are at least two reasons for making this knowledge explicit: graphic arts practice will benefit from a controlled scientific treatment, and automatic or semi-automatic production of images under computer control will become possible.


"We claim that these advances make the computer generation of high quality images in a variety of output media significantly closer to reality".

[Delete: in a variety of media]

NEW: across a variety of output media
-- it seems too strong to claim we're increasing the computer generation of high quality images in general. "Across" is better than "in", I think.


 "To understand our motivation in doing this research, it is worth giving
a short description of the project that made us aware that advances were
urgently needed in solving the cross-rendering problem".

[Delete: solving, i.e. needed in the cross-rendering problem.]

"A commitment
was made to prepare, in printable form, the images to appear in the
special issue of Color Research and Application that constituted the
proceedings for the 1986 AIC Interim Meeting on Color in Computer
Generated Displays."

[Who made the commitment: should this say: Xerox Palo Alto Research Center
made a commitment to ...?]

"Images were supplied in digital form by authors of
the conference papers and screened color separations were generated for
offset printing. Our need to bring this process under computer control
forced us to discover the principles and algorithms reported here. Of
course, such a project necessarily has a deadline, so that every
scientific opportunity cannot be followed and we had, at times, to be
satisfied with algorithms that "did the job", if not elegantly.
Nonetheless we believe that the principles we discovered significantly
advance the state of the art of digital color reproduction, and that
leads we were unable to follow point the way to a great deal of
productive research".
>
> Summer camp: wouldn't it be more accurate - and more politic! - to say
> that we used the project as a forcing function to elucidate means of
> attacking the cross-rendering problem, given that we knew there was a
> problem? I understood your primary reason for agreeing to the project
> was exactly this.
[My motivation in writing this in like this was to get the summer camp aspect
up front. Of course the project had a summer camp aspect. It's just not what
we are reporting in this paper. I gave a reference to the conference paper at
this point, commenting that it's where to go to find out more about the summer
camp aspect. This paper is about principles discovered in doing the summer
camp project. The idea is to get the issue up front and put it explicitly in
perspective. The stuff is down below. We might want to move it if the point
can be made more clearly.]
-- I think it's important to state clearly up front what we actually accomplished. I personally have much more respect for principles proposed by authors who have also practiced what they preach. I propose rewriting the whole paragraph, including the short one below it:

NEW: The project that acted as a forcing function for our work on the cross-rendering problem was a committment made by the Xerox Palo Alto Research Center to prepare, in printable form, the images illustrating the special issue of Color Research and Application that constitute the proceedings for the 1986 AIC Interim Meeting on Color in Computer Generated Displays. Images supplied in digital form by authors of the conference papers were used to produce screened color separations for offset printing. A short paper presented at the conference [Stone1] gave a narrative account of the project, but supplied little technical detail as it was written while the work was in progress. Because this was a real project with a real deadline, we were unable to pursue every scientific opportunity and occasionally had to be satisfied with algorithms that were merely adequate rather than elegant. However, we believe the principles discovered during this this project that we present here significantly advance the state of the art of digital color reproduction, and that leads we were unable to follow due to time pressures point the way to a great deal of productive research. Examples of images from Color Research and Application are used as illustrations throughout this paper.


 "The results reported here deal with the following aspects of the
cross-rendering problem. Given images defined by monitor coordinates,
not seen on the monitors for which they were produced, what
transformations should be performed on them before they are rendered
into a variety of color printers, with color offset being the definitive"
>
> "into a" -> "onto a" ?
>
[I would think "on a variety".]
NEW: "on a variety"


"from time to time we had to take somewhat arbitrary leaps over chasms of ignorance.
">
> "to take somewhat arbitrary leaps" -> "leap somewhat arbitrarily"
>
[This is one metaphor that just won't go away: we all like it too much! Since
it's meant to suggest impulsive boldness let's not undercut it with somewhat.
I suggest just "we had to leap arbitrarily over chasms ...". <-- John note:
Fowler says that there is logical punctuation and copy editor's punctuation;
one has common sense to recommend it, the other tradition. Not being an editor
I choose common sense.]
NEW: take arbitrary leaps


 ``The first step in cross-rendering is to precisely quantify both the
images to be rendered and the characteristics of the source and
destination devices''.
[This split infintive makes my hair stand on end: I suggest "is the precise
quantification of both the images ... and the characteristics ...". A small
increase in clarity at the cost of a little stylistic awkwardness can be
achieved by "precise quantification of the images ... and of the
characteristics ...". I would probably choose the latter.]
--It was your split infinitive originally, and I rather like it. However, I've unsplit it, knowing that the copy editor would probably do it for us anyway.
NEW: is to quantify precisely both..


 "In offset printing, a color separation is a halftone pattern used to
produce the printing plate for that color. The color separations used
to produce the printing plates are also used to produce a less expensive
color print that approximates the result of the printing process. Such
a print is called a color proof. The color separations and the proof
are sent to the printer, who adjusts the printing press to duplicate the
appearance of the color proof. Setting up an offset printing run is
expensive and time consuming, so the usual practice is to control only
the color proof".

>
> "control only the color proof". I think this gives the wrong impression -
> one hopes that the printer controls the printing run! Perhaps something
> like "the usual practise is to control proofs, which the printer then
> uses to control the printing run" would be better?
[Having no control, I suggest the following: "the customer usually approves the
proof copy, leaving the rest up to the printer.", or if we want to stay closer
to our work " the usual practice is to generate a calibrated proof copy,
leaving the control of the press up to the printer.".]

NEW: In offset printing, a color separation is a halftone pattern used to produce the printing plate for that color. These separations are also used to produce a color proof, which is a cheaper and simpler way of viewing the separations than setting up an offset press. Standard practice is to adjust the separations until the proof is satisfactory, and trust to the skill of the printer to to duplicate the appearance of the color proof on the printed page.


"To create a satisfactory
reproduction, it is necessary to modify the tristimulus values
significantly to accommodate the difference between the reproduction
properties of the printer and the monitor, a process we call gamut
mapping".
>
> "significantly" - for two similar gamuts, "significantly" seems like
> an overstatement.
[I agree: remove significantly.]
--but the sentence refers to printers and monitors, not to devices with similar gamuts. I like the significantly as it emphasizes that we are making a significant change with the gamut mapping.