What this covers
- Different line breaks means an unembedded font
- Proportionally smaller on paper means print scaling
- Check the fonts panel in the document properties
- Re-export with embedding rather than working around it
A PDF is supposed to look the same everywhere. That is the format's entire proposition, and it holds up remarkably well. When it fails, it is almost always one of three things.
Three causes, three symptoms
The symptoms are distinct enough to identify without guessing.
| Symptom | Cause | Fix |
|---|---|---|
| Line breaks fall in different places | Font not embedded, substituted | Re-export with embedding |
| Boxes or question marks where symbols were | Symbol font not embedded | Re-export with embedding |
| Page count differs between machines | Font substitution, text reflowed | Re-export with embedding |
| Everything proportionally smaller on paper | Print scaling | Set print scale to 100 per cent |
| Margins uneven on paper | Paper size mismatch | Resize the document to the paper |
| One reader shows a feature and another does not | Reader capability difference | Flatten, or accept it |
Unembedded fonts: the usual answer
A well-made PDF carries the fonts it uses inside it. When one is not embedded, the file names it and relies on the reader having it. If the reader does not, it substitutes the closest thing available.
Every typeface gives characters slightly different widths, so a substituted font pushes text along each line differently. Line breaks move, the divergence accumulates down the page, and a document that ended cleanly at the foot of page three now runs two lines onto page four.
The diagnosis is in the document properties: most readers list every font used and whether each is embedded. A font marked as not embedded, on a document that looks wrong elsewhere, is your answer.
Symbols fail worst
Text fonts substitute imperfectly. Mathematical and symbol fonts substitute catastrophically, because there is no sensible nearest match - the result is usually a page of empty boxes where the equations were. Each box is the reader saying it has no glyph for that character code.
Print scaling: not a rendering problem at all
If the document looks identical on screen and comes out of the printer proportionally smaller, nothing is wrong with the file. The print dialogue scaled it, which most systems do by default under a setting called fit to page or shrink oversized pages.
This matters far beyond appearance. Scaling changes every measured length on the page, so a printed graph gives wrong readings while looking entirely normal. Set the scale to 100 per cent, print one page, and measure a known length before printing a set.
Identifying which you have
About a minute.
- Compare on screen, not on paper
If the two machines show identical screens, the problem is printing rather than rendering.
- Check whether the page count matches
A different page count means the text reflowed, which means substitution.
- Open the fonts panel
In the document properties. Anything not marked embedded is a candidate.
- Look for boxes
Missing glyphs are unambiguous and nothing else produces them.
- If it is print only, check the scale setting
100 per cent or Actual Size, not fit to page.
Investigating and working around it
When you cannot re-export
If the document is not yours and you cannot get a properly embedded version, the options are limited. Rendering the pages to images fixes the appearance permanently, because an image cannot substitute anything - at the cost of the text layer, so the document stops being searchable.
That is a reasonable trade for a one-page handout that must look right, and a bad one for anything you will work from. Usually the better answer is to accept the substitution and check the content rather than the layout.
Reader differences, which are rarer than blamed
Occasionally two readers genuinely disagree: one implements a feature the other does not - certain annotation types, layers, unusual transparency. The symptom is a specific element present in one and absent in the other, rather than a general shift.
Flattening usually resolves it, by converting the feature into ordinary page content that every reader draws the same way. It is also the fix for the most common version of this: form fields visible in one reader and blank in another.
Before sending a document out
- Every font listed as embedded in the properties panel
- Opened on a second machine if the layout matters
- Page count checked on both
- Equations and symbols inspected specifically
- Form fields flattened if anyone will print it
- For printing, scale set to 100 per cent and paper size matched
Questions and answers
Why do line breaks change on another computer?
A font was not embedded, so the other machine substituted one with different character widths. That changes where lines break, and the difference accumulates down the page.
Why does my document have a different page count elsewhere?
Same cause. Substitution reflows the text, and a paragraph that fitted on one page now spills onto the next.
The document looks fine on screen but prints smaller. Why?
The print dialogue scaled it - fit to page is the default on many systems. Set the scale to 100 per cent, which matters particularly if anything on the page will be measured.
How do I check whether fonts are embedded?
Open the document properties and look at the fonts tab. It lists every font used and states whether each is embedded, usually alongside whether it is a subset.
