Compiled from 2 sources; we haven't tested this product ourselves yet. How we research
Quick answer
The MUJI High Quality Paper Open-Flat Lined Notebook is a lined notebook with 80 sheets (160 pages) that MUJI says opens flat so writing is easier. MUJI USA sells it in A5 (21 × 14.8 cm) and a B6 listed at 19.5 × 13.7 cm, and lists Japan as the country of origin.
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Notes on these facts
Made by Ryohin Keikaku Co., Ltd.. Made in Japan: MUJI USA's product details give "Country/Region of Origin: Japan" for both sizes. Source. Price: example listing.
Price bands are typical US retail, checked October 2026. Conversions to US dollars are approximate, at October 2026 rates (US$1 = ¥158 = ₩1,330 = NT$32.5 = CN¥6.7 = SEK 9.9 = DKK 6.7 = ₺49.6 = C$1.41 = A$1.43 = CZK 21.7; €1 = US$1.12; £1 = US$1.32; CHF 1 = US$1.21).
Key takeaways
MUJI USA lists two sizes: A5 at 21.0 × 14.8 cm (8.3 × 5.8 in) and a B6 at 19.5 × 13.7 cm (7.7 × 5.4 in).
Each has 80 sheets (160 pages) of horizontal-lined paper that MUJI calls high quality.
MUJI says the notebook opens flat to make writing easier; the listing gives no binding type beyond its Bind tag.
MUJI USA lists Japan as the country of origin.
Both sizes are in our $$ band ($5–20); the A5 costs about a dollar more than the B6.
What is the MUJI Open-Flat Lined Notebook?
It’s a notebook of high-quality, horizontally lined paper that MUJI says opens flat to make writing easier. MUJI is the brand of Ryohin Keikaku, the Japanese retailer. MUJI USA’s tags describe a bound notebook, but the page doesn’t name the binding.
It costs more than MUJI’s thin stitched notebooks and has far more sheets, so it’s closer to a main notebook than a pocket pad.
MUJI open-flat notebook specs
Spec
A5
B6 (as MUJI lists it)
Size
21.0 × 14.8 cm (8.3 × 5.8 in)
19.5 × 13.7 cm (7.7 × 5.4 in)
Sheets
80 (160 pages)
80 (160 pages)
Ruling
Horizontal lines
Horizontal lines
Barcode
4550002185237
4550002185626
Made in
Japan
Japan
MUJI USA gives no paper weight, line spacing or cover material. The B6 figure is larger than the 12.5 × 17.6 cm ISO B6 sheet, so MUJI’s number likely measures something else, but the page doesn’t say.
It suits people who want one lined notebook with plenty of pages that stays open under their hand.
Journaling and planning: 80 sheets (160 pages) of horizontal-lined paper that MUJI says opens flat for easier writing.
Skip it if you need to know how it handles fountain pen ink or highlighters: MUJI USA gives no paper weight.
How long does an 80-sheet notebook last?
80 sheets is 160 pages, so one page a day lasts about five months. That’s our arithmetic, not MUJI’s. It’s also 2.7 times the 60 pages of MUJI’s recycled paper notebook.
A sheet is one leaf with a page on each side. If you write on only one side to avoid show-through, you get 80 usable pages. MUJI USA gives no paper weight, so we can’t say whether the reverse side stays clean.
Which MUJI open-flat notebook size should you choose?
Choose the A5 if you want the common size; the B6 is only about a centimetre smaller each way. A5 is the size most planners and covers are built for, and at 8.3 × 5.8 in it fits easily inside a US letter (8.5 × 11 in) folder. See our A5 vs B5 notebooks guide for how sizes compare. The B6 costs about US$1 less when we read MUJI USA’s page on November 1, 2026.
How does it compare with other MUJI notebooks?
It has the most sheets of MUJI’s lined notebooks we cover, and it’s the only one MUJI says opens flat.
Our best notebooks roundup compares everyday notebooks across brands.
Where is the MUJI open-flat notebook made?
In Japan: MUJI USA gives it as the country or region of origin for both sizes.
How much does the MUJI open-flat notebook cost?
Both sizes are in our $$ band ($5–20). MUJI USA lists the A5 about a dollar above the B6. MUJI USA sells it as Final Sale, with no refunds or exchanges.
Frequently asked questions
How many pages does the MUJI open-flat notebook have?
MUJI USA lists 80 sheets, which is 160 pages, for both the A5 and the B6.
What size is the MUJI open-flat notebook?
MUJI USA lists an A5 at 21.0 × 14.8 cm (8.3 × 5.8 in) and a B6 at 19.5 × 13.7 cm (7.7 × 5.4 in).
Is MUJI's B6 the same as standard B6?
MUJI's figure of 19.5 × 13.7 cm is larger than the 12.5 × 17.6 cm ISO B6 sheet size. MUJI doesn't say what its figure measures, so treat it as the notebook's listed size.
Does the MUJI open-flat notebook really lie flat?
MUJI says it opens flat to make writing easier. We haven't tested it, and the listing doesn't name the binding.
Is the MUJI open-flat notebook ruled or dotted?
MUJI USA describes horizontal-lined paper. The product's tags mention dotted and grid layouts, but the description names only horizontal lines, so check the page you're buying.
Is the MUJI open-flat notebook good for fountain pens?
MUJI calls the paper high quality but gives no paper weight or ink test, so we can't say yet. Our best notebooks for fountain pens roundup lists tested options.
How is it different from the MUJI recycled paper notebook?
It has 80 sheets against 30, lies flat according to MUJI, and costs more: MUJI's recycled notebooks sit in our $ band.
