PDF to Plot: Why Your Prints Don’t Match What’s on Screen

You set up the sheet, it looks perfect on screen, and the print comes out wrong. Bold lines print hairline thin, your colors turn black, and a quarter inch scale does not measure a quarter inch on paper.

Take a breath. This is one of the most common drafting headaches, and it is usually a settings problem. Once in a while it is an out of date plotter driver. But start with the settings, because the settings are findable.

Here is the short version. Your print does not match your screen because it passes through two rulebooks, not one. Inside CAD, the plot style table (the CTB or STB file) sets the final lineweight, color, and shading of every line. Then, if you print the PDF instead of plotting straight to paper, your PDF reader gets a vote too, and its default is to shrink the page to fit. Fix the plot style table, set a real scale in both CAD and your PDF reader, and check the preview. That covers almost every case.

First, the key idea: there are two rulebooks

What you see in the drawing area is not what prints. The drawing runs through a separate set of rules first. In most offices, it runs through a second set after that.

Rulebook one is the plot style table. In plain English, it is a lookup sheet that tells the printer what to do with every line: how thick, what color, how dark. The common kind is a CTB (a color dependent plot style table), which maps each drawing color to a final print setting. A red line on your screen does not print “red and whatever thickness it looks.” It prints however the table says to print red.

Rulebook two is your PDF reader. This one surprises people. You plot a perfect PDF, open it in Adobe Acrobat or Bluebeam Revu, hit print, and the paper comes out at 94 percent of the right size. Nothing was wrong with your CAD file. Acrobat’s Page Sizing was set to “Fit” or “Shrink oversized pages,” so it quietly scaled your sheet down to match the paper in the tray.

So this is not a broken file, and it is not a broken plotter. It is two sets of rules doing what they were told, and nobody told them the right thing.

Preview beats the model screen every time. One real test plot catches the rest.

Problem 1: Colors come out wrong

You drew in color, and the print came out black, or gray, or a different color. That is the rulebook doing its job, just maybe not the job you wanted.

Many firms use a plot style on purpose that prints everything black. That is normal for construction drawings. The screen colors are there to organize layers, not to print. So colored lines printing black is often correct, not broken.

Trouble starts when the wrong table is attached. If a sheet grabs the wrong CTB, or none at all, colors and shading come out unexpected. Check which plot style table the sheet is using, and set the right one.

If lines look faded, look at screening. Screening is a setting inside the plot style table that controls how much ink hits the paper. The range is 0 to 100. Set it to 100 for full strength. Two notes: it only works if your plotter is set to color or grayscale with dithering on, and it is set per plot style (per color), not per layer.

Also, if your drawing has see through objects, transparency will not print unless “Plot Transparency” is checked.

For example, let’s say one sheet prints solid black and the next prints gray. Same drawing, different plot style attached. Point them both at the correct one, and they match.

What if your CTB is not even in the list?

You open the plot style dropdown to pick the office CTB and it is not there. There are two reasons.

The drawing is in the wrong mode. Every DWG is locked into one of two modes: color dependent (CTB) or named (STB). If your drawing is in named mode, no CTB will show up in the list at all. You have to convert it with the CONVERTPSTYLES command. Fair warning: once you convert a drawing from named to color, you cannot use CONVERTPSTYLES to go back.

The file is not where AutoCAD looks. Go to Options, Files tab, expand Printer Support File Path, then Plot Style Table Search Path. If your office CTB is not in one of those folders, it will not be listed. This is the top reason a new workstation cannot print like everyone else’s.

One thing you should not do. Do not edit the shared network CTB to fix your own sheet. Every drawing in the office uses that file. Change a pen assignment on Tuesday afternoon and you have changed every sheet on every job, including sets already out for bid. If a plot style needs to change, that is a conversation, not a quick fix.

Problem 2: Lineweights are too thin or too thick

This is the most common complaint. Bold lines print hairline thin, or everything prints the same weight with no hierarchy. Two settings cause it, and they fool people in opposite directions.

First, the rulebook again. The plot style table sets the final printed thickness of each line. If a color is mapped to a thin pen, it prints thin, even if it looks heavy on screen.

Second, a screen only toggle plays tricks. Show/Hide Lineweight (the LWDISPLAY system variable) changes how thick lines look on your screen and does nothing to the print. Turn it off and your lines look thin while printing fine. Turn it on and they look fat while printing normal. Either way, the screen lies.

About that “Plot object lineweights” checkbox

You will see two boxes in the plot dialog: “Plot with plot styles” and “Plot object lineweights.” A lot of advice online tells you to set both. You cannot.

When you turn on “Plot with plot styles,” AutoCAD turns on “Plot object lineweights” for you and greys it out. Autodesk says it plainly: that option is unavailable if Plot with Plot Styles is selected. It is by design. The plot style table is in charge of thickness now, so the other box has nothing left to do.

So there is one real decision. Leave “Plot with plot styles” on and the CTB drives everything, which is what most AEC firms want. Turn it off and objects print with their own assigned properties instead, ignoring the plot style overrides.

Then save it, or it will not stick

Everybody skips this step. If you fix the plot style table inside the Plot dialog and just hit OK, your fix goes out the door with the print. The next person opens the sheet and gets the old setting back.

Click “Apply to Layout,” or check “Save Changes to Layout,” before you plot. Better yet, set it in the Page Setup Manager. Page setups save with the sheet and can be pushed out to the whole team.

Problem 3: The scale is off

One quarter inch equals one foot (1/4″ = 1′-0″) does not measure right on paper. Check three places, in this order.

One: your PDF reader. Check this first. It is the fastest to fix and the most likely culprit. In Adobe Acrobat, open Print and look at Page Sizing. “Actual size” prints with no scaling. “Fit” scales small pages up and big pages down. “Shrink oversized pages” shrinks a big sheet to whatever paper is loaded without asking. For a drawing someone will measure, you want Actual size. In Bluebeam Revu, open Print and set Page Scaling to “None.” Bluebeam has a whole support article about PDFs not printing to scale from AutoCAD, because this comes up constantly.

For example, let’s say you plot a clean 24×36 PDF, then print it on the office 11×17. Your CAD file is perfect. The reader shrank it to fit, and now nothing on that sheet measures right.

Two: the plot scale in CAD. “Fit to Paper” stretches or shrinks the drawing to fill the sheet, which throws off any real world scale. Worth knowing: AutoCAD defaults to Fit to Paper when you plot from the Model tab, and 1:1 when you plot a layout. Fit is fine for a quick check print, as long as nobody scales off it. People do scale off check prints, so mark them.

Three: the viewport scale. On a layout sheet, each viewport (the window that shows your model on the sheet) has its own scale. Set it to match your title block, then lock it so it cannot drift. Heads up: a locked viewport also stops you from zooming inside it. That is the point, but it surprises people. Unlock, zoom, lock again.

Problem 4: Dashed lines print solid

Hidden lines, property lines, and center lines come out looking continuous. Dash length is controlled by linetype scale. LTSCALE sets the overall scale, MSLTSCALE handles model space, and PSLTSCALE handles paper space viewports. When dashes print solid, the linetype scale is too large or too small for that object. If your office template has these set oddly, everyone inherits the problem.

The plot preview: close, but not the paper

The plot preview is the best check you have. It shows the drawing after the plot style table is applied, which is exactly what the model screen cannot do. You should look at it before every plot.

You should also know what it will not catch. The preview is drawn by your computer. The print is made by the device.

Merge control lives in the plotter setup file (the PC3), not in your drawing. It decides what happens where two lines cross. “Lines Overwrite” means the top line hides the one underneath. “Lines Merge” blends the two colors into a third, so a magenta line crossing a yellow line prints red. Autodesk has a support article about plotting to PDF with Lines Merge on and getting blue lines nobody drew. Preview will not warn you. One relief: if your setup plots everything black, merge control does not apply.

The real printable area is the other blind spot. Every plotter has margins it physically cannot reach, so a border can clip on paper and still look fine in preview.

So preview catches the common stuff and beats the model screen every time. One real test plot catches the rest.

If you work in Revit, this works differently

Almost everything above is AutoCAD. Revit does not use CTB or STB files at all.

In Revit, lineweights come from Object Styles and the Line Weights dialog, both under the Manage tab. The screen toggle to know is Thin Lines. When it is on, every line draws at one width no matter the zoom or the real lineweight. That is the Revit version of the trick LWDISPLAY plays in AutoCAD.

For scale, go to File, Print, Print Setup, and set Zoom to 100 percent. That prints views at the scale in the view properties. “Fit to page” throws your scale off, same as “Fit to Paper” does in AutoCAD. Set Paper Size to match your title block too.

A simple way to get matching prints every time

Checking a preview every time is a good personal habit. It is not a system. If you want the whole office printing the same, build it into the setup instead of asking twelve people to remember twelve things.

• Share the plot styles. Put the office plot style tables in a shared folder, and add that folder to the Plot Style Table Search Path on every workstation.
• Build page setups into your template. Set the device, paper size, plot style table, and scale once, and save them as named page setups.
• Apply them the right way. Use the Page Setup Manager and Sheet Set Manager instead of setting the plot dialog by hand every time.
• Fix the PDF readers too. Set Acrobat to open on Actual size and Bluebeam Revu on None, on every machine.
• Then check the preview. It is the last gate before paper, and it takes two seconds.

Make one test plot and keep it. Draw a few lines in different colors mapped to different weights, plot it with the AutoCAD PDF (High Quality Print).pc3 driver, print it on the real plotter, and measure it. If the heavy lines are heavy, the light lines are light, and a scale rule reads true, your setup is good. Tape it inside the plotter cabinet.

Set it up once and the daily print headache goes away. Proactive beats fighting the plotter on every deadline.

Frequently asked questions

We will get your prints matching, firm-wide

Fixing one person’s plot settings is easy. Getting every workstation, plot style, and plotter set up so the whole office gets matching prints is the part that takes know how.

We help small architecture and engineering firms around Knoxville standardize their plotting setup, so a print looks the same no matter who hits the button. So your team can focus on the drawings, not on fighting the plotter before a deadline.

If your prints never match your screen, give us a call. We will sort out the plot styles, the templates, and the plotter, and tell you straight what was off. For getting those PDFs to clients cleanly, see our post on sharing large CAD files with clients.

Sources: Autodesk: Plot Dialog Box; Autodesk: About Setting Options for Plotted Objects; Autodesk: To Use Screening; Autodesk: LWDISPLAY (System Variable); Autodesk: CONVERTPSTYLES (Command); Autodesk: Unable to switch plot style type in Page Setup or Plot dialog; Autodesk: To Find Plot Style Files; Autodesk: About Plot Color Merge Control; Autodesk: Plotting to PDF with Lines Merge produces plot with blue lines; Autodesk: LTSCALE and PSLTSCALE system variables; Autodesk: Sheets are not printing to scale in Revit; Autodesk: How to modify line weights in Revit; Adobe: Scale or resize printed pages in Acrobat and Reader; Bluebeam: Printing from Revu; Bluebeam: PDF isn’t to scale when printing from AutoCAD