The standard newspaper puzzle
A medium grid is what most newspapers print: enough clues that the opening is comfortable, few enough that you will need pointing pairs or a similar move to finish. Ten to fifteen minutes each, and a pack of six fills an afternoon.
Leave room for pencil marks
If you write candidates in the corners of cells, print one or two per page rather than four. At two per page the cells are about 13 mm across, which is enough for small pencil marks in a sharp pencil.
You can also play medium puzzles online, where the notes tool keeps your candidates up to date automatically.
How much space you need
A medium puzzle usually needs candidate marks in ten or fifteen cells rather than all of them, so two puzzles per page is comfortable for most solvers. At that size each cell is about 13 mm across — enough for three small digits in a row if you write neatly.
Building a booklet
Ask for 25 or 50 puzzles, choose two per page, and tick the answer sheet. Printed double-sided, that is a booklet you can staple: puzzles at the front, answers at the back, nothing to look up online.
For a mixed pack, print a set of these, then a set of easy and a set of hard puzzles, and interleave them. Puzzle books sold in shops are put together the same way.
Common questions
How hard are these?
Every grid needs at least one technique beyond plain scanning, but none needs pairs, wings or fish.
How long does one take?
Usually 8 to 15 minutes on paper.
Can I get a booklet?
Choose 25 or 50 puzzles and print two or four to a page — the answer sheet at the end is numbered to match.
Do the puzzles repeat if I print several sets?
No. Each set is generated fresh, and the chance of the same grid appearing twice is vanishingly small.