Covers in more than one script
Start with the fact that causes most of the damage: a display typeface picked for its Latin letters usually has no coverage for any other script whatsoever. It holds A to Z, a handful of accents, some punctuation, and nothing else.
Type your title in another script into that face and nothing announces the problem. The software quietly substitutes whatever it can find on the system, and what you get is a cover set in two unrelated designs — your chosen face for anything Latin, some default for the rest. To a reader of that script the cover looks broken. To you, if you do not read it, it looks fine.
You cannot proof a script you do not read
This is the part to accept early, because everything else follows from it.
A native reader sees in one second what you cannot see at all: a substituted font, a letter that has taken the wrong form, a character that is close to the right one and is not it. None of that is visible to someone working from shapes.
So find a reader before you publish, not after. Ask three specific questions rather than "does this look right", which gets a polite yes: does every character look like it belongs to the same design? Is anything spelled or joined wrongly? Would you know, from the cover alone, that this was made by somebody who reads the language?
If the book is a translation you commissioned, the translator is the obvious person to ask, and the ask is small — Having your book translated covers setting that relationship up so a question like this one is easy to send. Translations and foreign rights, for a self-published author covers that relationship.
What changes typographically
Vertical proportions differ. Latin type is built around an x-height with ascenders and descenders above and below it. Other scripts distribute their mass differently — some hang from a line above, some occupy a squarer body with almost no ascender at all. A title that balances optically in Latin sits visibly too high or too low when the same line is set in another script. Re-center by eye every time; do not trust the position that worked before.
Some scripts connect, and cannot be letterspaced. Arabic and its relatives join letters into words, and the joins are part of the letterforms. Pulling them apart the way you would open up a Latin all-caps title does not make it airier, it breaks the word. If a line needs more presence, change the size or the weight, not the tracking.
Some scripts read right to left, and that reverses the composition. The eye enters from the other side, so the arrangement that led a Latin reader into the title now leads them out of it. For a printed book it goes further: a right-to-left book opens from what a Latin-script reader would call the back, and the spine reads the other way. That decides which panel of the wrap carries the front cover artwork, so settle it with your printer before you build the file rather than after you upload it.
Line breaks are not yours to guess. Where a long title may be split across two lines is a question about the language. Ask; do not break it where it looks balanced. Setting a long title without shrinking it covers the Latin-side craft of the same problem.
In the Cover Maker. Title, series and author stay live vector text rather than being baked into the artwork, so changing a line after a native reader looks at it is an edit, not a redraw. It also checks the cover at thumbnail size, which is where a mismatched second face shows up first. Start your cover → · about the Cover Maker
Bilingual covers: decide which language leads
The instinct on a two-language cover is to give both languages equal size, weight and space. It reliably serves neither: two titles of the same size compete, the eye does not know where to start, and the cover reads as a document rather than a book.
Pick the language that leads — usually the language of the market you are selling into, or the one the buyer is searching in. Set it as the title, full size and full weight, the thing the design is built around, and set the other smaller and quieter above or below it, the way a subtitle behaves. The second language is still there, still findable, and no longer fighting. The same logic settles the author name: one setting, once, unless the name is genuinely written differently in the two scripts.
Two faces from two different scripts will never match the way two Latin faces can, so aim for compatible weight and proportion rather than a family resemblance, and let the size difference carry the hierarchy. The reasoning in Pairing typefaces on a cover still applies; the tolerances are wider.
Check the export, not the screen
Missing glyphs are the classic failure here, and the editing view is the worst place to catch them, because it draws with every font on your machine and a printer has none of them.
Open the exported file and look at the actual characters. Zoom in. Compare against the text you pasted in, and have your native reader look at the export rather than a screenshot of the editor. A character that has silently become a box, a blank, or a letter from a different design will be sitting there in the file that goes to the printer. Checking your fonts are really embedded is the general version of this check.
The barcode, the ISBN and the store metadata are separate questions with their own rules, and the script of your title does not change them — see Barcodes, and the price code beside them and Selling the same book in more than one country.
For the inside of the book, a bilingual interior is a different problem with a different answer, worked through in Bilingual books and facing-page layout.
Make your cover
The Cover Maker is free to use: name your book, bring your artwork, and it draws the full wrap — front, spine and back — to your printer's own measurements. You only pay when you want the files without the preview watermark.
Next: Bilingual books and facing-page layout · More: Setting a long title without shrinking it · Accents, symbols and characters that go missing · Pairing typefaces on a cover