How to Prepare an InDesign File for Translation — A Guide for Designers and Project Managers
There is a moment every DTP specialist knows well. The translated IDML file arrives, it gets opened in InDesign, and within thirty seconds it is clear that the original document was built by someone who had never heard the word "translation" and possibly also had a complicated relationship with paragraph styles.Overflowing text frames. Manual spacing everywhere. Text embedded inside images. Font sizes adjusted line by line. Tables built from individual rectangles drawn by hand.
This guide exists so that moment happens less often.Whether you are a designer creating documents that will eventually be translated, or a project manager at a translation agency responsible for delivering clean files to a DTP specialist, the steps below will save time, reduce cost, and prevent a significant amount of mutual suffering.
Why File Preparation Matters More Than You Think
When a document is built without translation in mind, every language version becomes a manual reconstruction job. The DTP specialist cannot simply drop in the translated text and call it done. Instead, they spend time cleaning up formatting, resolving overset text, rebuilding tables, and applying styles that should have been there from the beginning.
This takes longer. Longer means more expensive. And in a 20-language project, the cost of a poorly prepared source file is multiplied across every single language version.
The good news: most of the preparation work takes almost no extra time when done at the design stage. It becomes very expensive only when done retroactively across 20 translated files.
1. Use Paragraph and Character Styles for Everything
This is the single most impactful thing a designer can do for a multilingual project, and it is also the rule most frequently ignored.
Every heading, body paragraph, caption, bullet point, table cell, and footnote should have a named paragraph style applied to it. Every instance of bold, italic, or small caps within a text frame should use a character style, not a manual override applied with Ctrl+B.
Why does this matter for translation? When IDML files are processed through CAT tools like SDL Trados or memoQ, manual formatting overrides are frequently lost or scrambled on export. A document built entirely with styles will come back from the CAT tool with its formatting intact. A document built with manual overrides will come back looking like it was formatted by a particularly determined toddler.
Styles also allow the DTP specialist to make global adjustments quickly; reducing the font size by half a point across all body text in a condensed German translation, for example, takes seconds with styles and a very long time without them.
2. Leave More White Space Than You Think You Need
Translated text is almost never the same length as the source. This is not a translation error; it is simply how languages work.
As a general rule, English text expands when translated into most European languages. French and Spanish typically run 20 to 30 percent longer. German can expand by 30 percent or more and also produces words of considerable ambition in terms of length. Russian and Polish are similarly generous. Japanese and Chinese, by contrast, are often more compact than English.
What this means in practice: a text frame filled edge to edge with English body copy will overflow in German. A headline that fits perfectly in English may need two lines in French.
The fix at the design stage is simple: leave breathing room. Do not pack text frames to their absolute limit. Do not set font sizes at the absolute minimum acceptable size; the DTP specialist will need to go smaller in some languages, and there is only so far that can go before the text becomes illegible.
A useful test is to add 30 percent more dummy text to every text frame before finalising the layout. If it still looks acceptable, the document will survive translation. If it immediately breaks, the design needs more flexibility.
3. Do Not Embed Text Inside Images
This one causes genuine pain and it happens constantly.
When text is part of an image file, it cannot be extracted by a CAT tool. The translator cannot access it. The DTP specialist cannot edit it directly. Every piece of embedded image text must be recreated separately, in every language, by opening the original image file, editing it, re-exporting it, and relinking it in InDesign. In a 15-language project, that is 15 separate image edits per image.
The alternative is simple: create the image without text in the design software, link it into InDesign, and place the text in a separate InDesign text frame positioned over the image. The text is then part of the IDML file, translated automatically by the CAT tool, and requires no special handling during DTP.
This works for most infographics, diagrams, and photo captions. There are cases where text genuinely must be part of the image file for design reasons; when that happens, always keep the original editable source file and make sure it is included in the project package.
4. Use InDesign Tables, Not Manually Drawn Boxes
Tables built from individual text frames and hand-drawn lines look like tables but do not behave like them. When translated text expands, each cell has to be resized manually because nothing is connected to anything else.
InDesign has a proper tables feature. When a real InDesign table is used, cells adjust automatically as content expands. The DTP specialist can resize a column once and the entire structure updates. This is a meaningful time saving in documents with many tables, such as technical manuals, product catalogues, and annual reports; the kinds of documents that tend to be translated into many languages.
Building tables correctly from the start takes no longer than building them manually. It saves a considerable amount of time later.
5. Thread Text Frames Correctly
Threading connects text frames so that content flows from one to the next. This is how multi-column layouts and long documents should always be built.
Unthreaded text frames each contain their own isolated block of text. When translated text expands, each frame overflows independently and must be adjusted separately. Threaded frames allow text to reflow naturally across the connected chain, which reduces the number of manual adjustments needed after translation.
Threading also affects how CAT tools segment and parse the file. Properly threaded text is processed as continuous content; isolated frames are processed as separate segments, which can create awkward translation breaks mid-sentence.
6. Export as IDML, Not INDD
An INDD file is the native InDesign format and is version-specific; a file saved in InDesign 2024 may not open correctly in an earlier version of the software. An IDML file is the InDesign Markup Language format, which is backward compatible and can be opened in any version of InDesign from CS4 onwards.
More importantly, IDML is the format that CAT tools like SDL Trados, memoQ, and Wordfast can read and process directly. Sending an INDD file to a translation agency is the equivalent of sending a locked box: it may or may not be openable depending on the software version at the other end, and it will cause delay while everyone works out what to do about it.
Always export IDML before sending files for translation. In InDesign, go to File, then Export, and choose InDesign Markup (IDML). It takes about three seconds.
6. Export as IDML, Not INDD
An INDD file is the native InDesign format and is version-specific; a file saved in InDesign 2024 may not open correctly in an earlier version of the software. An IDML file is the InDesign Markup Language format, which is backward compatible and can be opened in any version of InDesign from CS4 onwards.
More importantly, IDML is the format that CAT tools like SDL Trados, memoQ, and Wordfast can read and process directly. Sending an INDD file to a translation agency is the equivalent of sending a locked box: it may or may not be openable depending on the software version at the other end, and it will cause delay while everyone works out what to do about it.
Always export IDML before sending files for translation. In InDesign, go to File, then Export, and choose InDesign Markup (IDML). It takes about three seconds.
7. Turn Off Track Changes Before Exporting
InDesign has a Track Changes feature. If it is active when the file is exported to IDML, the tracked changes are included in the exported file and can cause parsing problems in CAT tools, producing duplicate content, scrambled segments, or outright errors.
Before exporting to IDML, go to Edit, then Track Changes, then Accept All Changes. Then turn off Track Changes entirely. Then export.
This is a small step that prevents a surprisingly large amount of confusion.
8. Think About Fonts Before Choosing Them
Many fonts support Latin characters only. A font that works perfectly for an English, French, or German document will display as a series of empty boxes or substituted characters when the same IDML file is opened with Arabic, Chinese, or Thai text inserted by the translator.
Before finalising font choices for a document that will be translated into non-Latin scripts, check the font's glyph coverage. For projects involving Arabic or Hebrew, the font must support right-to-left text and proper glyph shaping. For Chinese, Japanese, and Korean, a separate CJK-compatible font will almost certainly be needed regardless of what the Latin font is.
The practical approach: confirm which target languages are in scope before choosing fonts, and check with the DTP specialist or translation agency before locking in a typeface. Changing a font after translation has begun is not impossible, but it creates extra work and occasionally also creates interesting conversations.
9. Do Not Convert Text to Outlines
Converting text to outlines turns letters into vector shapes. The result looks identical on screen but the text becomes completely uneditable. It cannot be extracted by a CAT tool, it cannot be modified by a DTP specialist, and it cannot be reflowed or resized without redrawing it.
If text must be outlined for a specific design reason, such as for a logo or a decorative heading, keep the original live text version in the file on a separate hidden layer. This allows the DTP specialist to work with the editable version and simply re-outline it after any changes.
10. Package and Deliver Files Properly
An InDesign file without its linked images and fonts is like a recipe without ingredients: technically present, practically useless.
When delivering files for translation or DTP, always use InDesign's Package function (File, then Package) to collect the document, all linked images, and all fonts into a single folder. Include the IDML export alongside the INDD file. Write a brief note explaining any unusual elements: text that should not be translated, specific font preferences for non-Latin scripts, or layout constraints that the DTP specialist should be aware of.
A well-packaged file with a short handover note arrives as a project that can start immediately. A bare INDD file with missing links arrives as a project that starts with a conversation about missing links.
What Happens When None of This Is Done
For the curious: here is what the DTP side looks like when a document arrives with none of the above in place.
The file opens and immediately shows pink boxes indicating missing fonts. Once those are resolved, preflight reveals 47 overset text frames. The tables are made of individual rectangles that bear no relationship to each other structurally. Every text frame uses a different manually applied font size. Several images have text baked directly into them with no source files provided. Track Changes was left on, so the IDML export contains both the original and revised versions of approximately 200 text segments.
This is not hypothetical. It is a Tuesday.
The document can still be processed. It will simply take three times as long and cost correspondingly more. And in a 20-language project, that cost multiplies accordingly.
Good file preparation is, in the end, not about making things easier for the DTP specialist. It is about keeping the project on time and on budget. Which is, presumably, also the goal of the person who built the file in the first place.
A Quick Checklist Before Sending Files for Translation
→ Paragraph and character styles applied throughout
→ Adequate white space in all text frames
→ No text embedded inside images
→ Tables built using the InDesign tables feature
→ Text frames threaded correctly
→ IDML exported and included in the package
→ Track Changes turned off before export
→ Font compatibility checked for all target languages
→ Text not converted to outlines
→ Files packaged with all links and fonts included
If all ten are in place, the DTP side of the project will run smoothly. If most are in place, it will run acceptably. If none are in place, it will still get done; it will just feel like more of an adventure than anyone planned for.
For questions about file preparation or to send files for a free assessment, use the contact page.