Do not use ImageSize, ImageResolution, AllowRasterization, Rasterize. These functions will convert a vector graphic to a raster. I have had good results using PDF export. After I export the PDF, I edit the PDF as text using notepad or notepad++. Search for /interpolate. When you find it change /interpolare=on to /interpolate=off.
UPDATE: I tested this today. ...
It seems like there are two main problems.
One is the shape of the polygons
test = Graphics@Polygon[Join[\[ScriptCapitalC]a[], \[ScriptCapitalC]b[], \
Gives this in the PDF:
Plotting the points gives a clue to why:
ListPlot[Join[\[ScriptCapitalC]a[], \[ScriptCapitalC]b[], \
\[ScriptCapitalC]c[]], Joined -> True, ...
We have two questions: 1) How to make a PDF from a grid of graphics (output of Plot), and 2) How to make a PDF for a whole notebook.
For the second question... Here's a way to make a PDF of a whole notebook including inputs and outputs. NotebookPrint saves a print-ready form of a notebook to a file in the format indicated by a file extension. First, open a ...
On an Apple, simply printing to a file works.
Why not print to a file, and then see what your print settings are set at?
Can you print to a printer?
UPDATE (see comments below)
Please try updating to Mathematica Version 12.1 or 12.2.
In V12.0, I get graphics to be broken across pages if I set their ImageSize to be wider than the page width, even though PageBreakWithin is set to False. For instance, it happens with ImageSize -> 1000 for me, which setting is the same as in the OP.
Try ImageSize -> Full if you want the graphics as wide as the page.
[In V12.1/12.2, the graphics are ...