diff --git a/collects/plot/common/contract.rkt b/collects/plot/common/contract.rkt
index 9bb73ec5c8..52d82a819f 100644
--- a/collects/plot/common/contract.rkt
+++ b/collects/plot/common/contract.rkt
@@ -33,8 +33,6 @@
                                                 'bdiagonal-hatch 'fdiagonal-hatch 'crossdiag-hatch
                                                 'horizontal-hatch 'vertical-hatch 'cross-hatch)))
 
-(defcontract plot-font-size/c (and/c real? (>=/c 0)))
-
 (defcontract font-family/c (one-of/c 'default 'decorative 'roman 'script 'swiss
                                      'modern 'symbol 'system))
 
diff --git a/collects/plot/scribblings/contracts.scrbl b/collects/plot/scribblings/contracts.scrbl
index b3bf49b241..5f4c713366 100644
--- a/collects/plot/scribblings/contracts.scrbl
+++ b/collects/plot/scribblings/contracts.scrbl
@@ -8,20 +8,43 @@
 
 @section{Convenience Contracts}
 
-@doc-apply[treeof]
+@doc-apply[treeof]{
+Identifies trees of values that meet the contract @(racket ct).
+Used by @(racket plot) and @(racket plot3d) to construct the contract for a tree of @(racket renderer2d?) or @(racket renderer3d?).
+}
 
 @section{Appearance Argument Contracts}
 
-@doc-apply[anchor/c]
+@doc-apply[anchor/c]{
+The contract for @(racket anchor) arguments and parameters, such as @(racket plot-legend-anchor).
+}
+
 @doc-apply[color/c]
-@doc-apply[plot-color/c]
-@doc-apply[plot-pen-style/c]
-@doc-apply[plot-brush-style/c]
-@doc-apply[font-family/c]
-@doc-apply[point-sym/c]
+@doc-apply[plot-color/c]{
+The contract for @(racket #:color) arguments, and parameters such as @(racket line-color) and @(racket surface-color).
+For the meaning of integer colors, see @(racket ->pen-color) and @(racket ->brush-color).
+}
+
+@doc-apply[plot-pen-style/c]{
+The contract for @(racket #:style) arguments (when they refer to lines), and paramters such as @(racket line-style).
+For the meaning of integer pen styles, see @(racket ->pen-style).
+}
+
+@doc-apply[plot-brush-style/c]{
+The contract for @(racket #:style) arguments (when they refer to fills), and parameters such as @(racket interval-style).
+For the meaning of integer brush styles, see @(racket ->brush-style).
+}
+
+@doc-apply[font-family/c]{
+Identifies legal font family values. See @(racket plot-font-family).
+}
+
+@doc-apply[point-sym/c]{
+The contract for the @(racket #:sym) arguments in @(racket points) and @(racket points3d), and the parameter @(racket point-sym).
+}
 
 @defthing[known-point-symbols (listof symbol?)]{
-A list containing the symbols that are valid @(racket points) labels.
+A list containing the symbols that are valid @(racket points) symbols.
 
 @interaction[#:eval plot-eval
                     (require (only-in srfi/13 string-pad-right))
@@ -34,8 +57,27 @@ A list containing the symbols that are valid @(racket points) labels.
 
 @section{Appearance Argument Sequence Contracts}
 
-@doc-apply[plot-colors/c]
-@doc-apply[plot-pen-styles/c]
-@doc-apply[pen-widths/c]
-@doc-apply[plot-brush-styles/c]
-@doc-apply[alphas/c]
+@doc-apply[plot-colors/c]{
+The contract for @(racket #:colors) arguments, as in @(racket contours).
+If the contracted value is a function, it is intended to take a list of values, such as contour values, as input, and return a list of colors.
+The number of colors need not be the same as the number of values.
+If shorter, they will cycle; if longer, some will not be used.
+
+See @(racket color-seq) and @(racket color-seq*) for a demonstration of constructing arguments with this contract.
+}
+
+@doc-apply[plot-pen-styles/c]{
+Like @(racket plot-colors/c), but for line styles.
+}
+
+@doc-apply[pen-widths/c]{
+Like @(racket plot-colors/c), but for line widths.
+}
+
+@doc-apply[plot-brush-styles/c]{
+Like @(racket plot-colors/c), but for fill styles.
+}
+
+@doc-apply[alphas/c]{
+Like @(racket plot-colors/c), but for opacities.
+}
diff --git a/collects/plot/scribblings/params.scrbl b/collects/plot/scribblings/params.scrbl
index ce47392105..687f4e364e 100644
--- a/collects/plot/scribblings/params.scrbl
+++ b/collects/plot/scribblings/params.scrbl
@@ -23,16 +23,24 @@ before using @(racket plot) or @(racket plot3d).}
 @doc-apply[plot-width]
 @doc-apply[plot-height]{The width and height of a plot, in logical drawing units (e.g. pixels for bitmap plots).}
 
-@doc-apply[plot-jpeg-quality]
-@doc-apply[plot-ps-interactive?]
-@doc-apply[plot-pdf-interactive?]
+@doc-apply[plot-jpeg-quality]{
+The quality of JPEG images written by @(racket plot-file) and @(racket plot3d-file). See @(method bitmap% save-file).
+}
+
+@doc-apply[plot-ps-interactive?]{
+If @(racket #t), @(racket plot-file) and @(racket plot3d-file) open a dialog when writing PostScript files. See @(racket post-script-dc%).
+}
+
+@doc-apply[plot-pdf-interactive?]{
+If @(racket #t), @(racket plot-file) and @(racket plot3d-file) open a dialog when writing PDF files. See @(racket pdf-dc%).
+}
 
 @section{Axis Transforms}
 
 @doc-apply[plot-x-transform]
 @doc-apply[plot-y-transform]
 @doc-apply[plot-z-transform]{
-Per-axis, nonlinear transforms. Set these, for example, to plot with log-scale axes.
+Per-axis, nonlinear transforms. Set these, for example, to plot with log-scale axes. See @(racket log-transform).
 }
 
 @doc-apply[id-transform]{
@@ -44,7 +52,7 @@ A log transform. Use this to generate plots with log-scale axes. Any log-scaled
 
 @examples[#:eval plot-eval
                  (parameterize ([plot-y-transform  log-transform])
-                   (plot (function (λ (x) x) 1 2)))
+                   (plot (function (λ (x) x) 0.01 1)))
                  (parameterize ([plot-x-transform  log-transform])
                    (plot (function (λ (x) x) -1 1)))]
 }
@@ -66,7 +74,10 @@ The @(racket freq) parameter controls the ``shakiness'' of the transform. At hig
 @section{General Appearance}
 
 @doc-apply[plot-foreground]
-@doc-apply[plot-background]{The plot foreground and background color. That both are @(racket 0) by default is not a mistake: for foreground colors, @(racket 0) is interpreted as black; for background colors, @(racket 0) is interpreted as white. See @(racket plot-color/c) for details on integer-indexed colors.}
+@doc-apply[plot-background]{
+The plot foreground and background color.
+That both are @(racket 0) by default is not a mistake: for foreground colors, @(racket 0) is interpreted as black; for background colors, @(racket 0) is interpreted as white.
+See @(racket ->pen-color) and @(racket ->brush-color) for details on how PLoT interprets integer colors.}
 @doc-apply[plot-foreground-alpha]
 @doc-apply[plot-background-alpha]{The opacity of the background and foreground colors.}
 @doc-apply[plot-font-size]{The font size of the title, axis labels, tick labels, and other labels, in drawing units.}