Getting the list in
One item per line. A line that starts with a space or a tab becomes a sub-item, indented under the one above and set slightly smaller — that is how "Drill and bits" gets "Impact driver" and "Spare battery" hanging off it. Leading hyphens, asterisks and bullet characters are stripped, so you can paste straight out of a doc, a note or an email without cleaning it up first. Blank lines are dropped.
Two hundred items is the cap, and hitting it is a sign the list wants splitting. A sheet somebody actually works down is rarely more than fifty lines.
Spacing, columns and the shape of the box
Row spacing is the setting that matters most and the one people skip. Tight fits the most lines and leaves no room to write anything beside them. Roomy nearly doubles the row height, which is what you want when each item gets a serial number, a quantity or a note written in next to it — an equipment check-out or a punch list, not a packing list. Two columns roughly doubles the capacity of a page and is worth turning on past about 25 items, though it makes writing in the left column awkward for right-handers.
Square boxes suit a tick or an X. Circles suit being filled in solid, which reads better from a distance. The blank line option drops the box entirely and leaves a short rule, for lists where you write a value rather than confirm a step — meter readings, counts, temperatures.
The Markdown copy
The same list comes out as - [ ] item lines with sub-items indented two spaces. That syntax renders as clickable checkboxes in GitHub and GitLab issues, in most note apps, and in anything else that speaks GitHub-flavoured Markdown. Everything is unchecked, since the point of generating a list is that nothing has been done yet.
Where a paper copy still beats an app
Anywhere your hands are dirty, wet or gloved, anywhere signal drops, and anywhere the list has to be handed to someone else and handed back. Pre-trip vehicle checks, close-down routines, event set-up, a punch list walked with a client, a load-out for a job. Turning on the signature and date line at the bottom makes it a record rather than a reminder, which matters if anyone is ever going to ask whether a step was done.
Questions people ask
My indented lines are not indenting.
The line has to begin with an actual space or tab. A hyphen with no space in front of it is read as a bullet marker on a normal item and gets stripped. If you pasted from an editor that converts leading tabs, retype one space at the front of the line.
Can I make a list with some items already checked?
No. Both the printed sheet and the Markdown come out empty, because a checklist that arrives partly checked is a checklist nobody reads carefully. Mark them once the list exists.
How many items fit on a page?
Roughly 40 at normal spacing in one column, about 55 tight, and around 25 roomy. Two columns close to doubles each of those figures. The result panel warns you when the list is going to run over.
Can I add a second column for quantities?
Not as a column, but roomy spacing leaves enough height beside each line to write a number, and the right-hand third of the row is empty in one-column mode. For a real table with headings, this is the wrong tool.