Hard · 50 puzzles · 16×16 to 20×20

50 hard nonograms that argue back.

Fifty nonograms from 16×16 to 20×20 for solvers who want the long version. These are graded hard because of how much reasoning they demand, not because the grid is wide.

3.99 EUR

Instant download · five PDFs in one purchase · personal use only

A hard 20x20 nonogram on an e-ink tablet resting on linen, next to a stylus and coffee

A hard puzzle here gives you an opening and then a wall. Getting past it means picking a candidate placement, chasing its consequences several moves deep, and eliminating it by contradiction. It is the skill a hard sudoku asks for, applied to runs instead of digits, and you should expect to put one down and come back to it.

Because every grid was verified to have exactly one solution, that reasoning is always safe: a contradiction proves the placement wrong. You will not lose an hour to a puzzle that had two answers all along.

The tablet editions run to 105 pages and are hyperlinked in both directions, with a full solution page for every puzzle. If you want to check a single deduction rather than the whole grid, the answer is one tap away and the way back is one more.

Five sizes, ten puzzles at each.

The first two sizes are shared with the medium volume. A 16×16 here is graded hard on how it solves, not on how wide it is.

16×16
17×17
18×18
19×19
20×20

What you download

Five files, one purchase.

Print

Sized to the paper, with the margins already set.

  • US Letter8.5 × 11 in…-letter.pdf
  • A4210 × 297 mm…-a4.pdf

E-ink

Sized to the screen. Links take you from the index to a puzzle and back from its answer.

  • reMarkable 21404 × 1872 px…-rm2.pdf
  • reMarkable Paper Pro1620 × 2160 px…-rmpp.pdf
  • Kindle Scribe1860 × 2480 px…-scribe.pdf

The same 50 puzzles are in every file. Only the page layout changes.

Is this the right one?

  • Medium nonograms go down without a pause.
  • One puzzle should last the evening.
  • Proving a square empty pleases you more than filling one in.

Not sure? The free sample has five puzzles in all five formats, with no email address or account. It is the same layout the books use, so it also tells you whether the pages sit well on your device.

Choose a level.

Free sample