I am trying to ascertain how large a justified text block will be when printed by rasterizing it in the "Printout" style environment. However, Rasterize is reverting to the "Working" environment. How can I obtain a raster of the graphic as it appears in "Printout" style?
The following code illustrates the problem. Note the text differs in size in the two environments: In the "Printout" environment the text occupies eight lines, but in the rasterised "Working" version it takes up only seven lines.
I am using text height prediction for page layouts.
SetOptions[EvaluationNotebook[], ScreenStyleEnvironment -> "Printout"]; lorem = StringTake[ExampleData[{"Text", "LoremIpsum"}], {198, 922}]; {wd, ht} = {564, 120}; box = Graphics[{Green, Rectangle[{0, 0}, {wd, ht}], Black, Inset[TextCell[lorem, LineSpacing -> {0, 16}, TextJustification -> 1], {0, 0}, {Left, Bottom}, {wd, Automatic}]}, BaseStyle -> {FontFamily -> "Times", FontSize -> 13}, PlotRange -> {{0, wd}, {0, ht}}, ImageSize -> wd] Rasterize[box] 
The notebook screen environment can be restored with the following statement:
SetOptions[EvaluationNotebook[], ScreenStyleEnvironment -> Inherited] Edit
Further to george2079's suggestion I made an automated procedure to produce a rasterised "Printout" graphic. It is subsequently processed in a separate procedure (not shown here) to ascertain the height of the text box required for print output.
createPrintBox[text_] := Module[{wd = 564, ht = 120, nb}, nb = CreateDocument[ExpressionCell[ Graphics[{Green, Rectangle[{0, 0}, {wd, ht}], Black, Inset[TextCell[text, LineSpacing -> {0, 16}, TextJustification -> 1], {0, 0}, {Left, Bottom}, {wd, Automatic}]}, BaseStyle -> {FontFamily -> "Times", FontSize -> 13}, PlotRange -> {{0, wd}, {0, ht}}, ImageSize -> wd], "Print"], ScreenStyleEnvironment -> "Printout", Visible -> False]; SelectionMove[nb, Next, Cell]; FrontEndExecute[FrontEndToken[nb, "CopySpecial", "MGF"]]; SelectionMove[nb, After, Cell]; FrontEndExecute[FrontEndToken[nb, "Paste"]]; SelectionMove[nb, All, Cell]; cellcontent = NotebookRead[nb]; NotebookClose[nb]; output = ToExpression[First@cellcontent]; Rasterize[Show[output, ImageSize -> wd]]] lorem = StringTake[ExampleData[{"Text", "LoremIpsum"}], {198, 922}]; printoutbox = createPrintBox[lorem] 
As you can see, this is a useable raster image showing the correct "Printout" style, justified text height of eight lines.
In contrast, here is the seven line "Working" screen-style raster produced by the code below:-

lorem = StringTake[ExampleData[{"Text", "LoremIpsum"}], {198, 922}]; {wd, ht} = {564, 120}; Rasterize[Graphics[{Green, Rectangle[{0, 0}, {wd, ht}], Black, Inset[TextCell[lorem, LineSpacing -> {0, 16}, TextJustification -> 1], {0, 0}, {Left, Bottom}, {wd, Automatic}]}, BaseStyle -> {FontFamily -> "Times", FontSize -> 13}, PlotRange -> {{0, wd}, {0, ht}}, ImageSize -> wd]]