Sliders answer what. These pages answer why, and why not.
The workbench can put any value you like behind a subject in about four seconds. Almost nothing that goes wrong afterwards is a question the workbench can answer. A portal refuses an upload and gives no reason. A finished photograph looks subtly assembled and nobody can say which part of it is lying. An outline that was perfect on a phone screen turns into a cardboard cut-out when the file opens at full size. Those are questions about photographs and about the bodies that ask for them, and they are what is written down here.
Each page was written from the complaint that brings people to it rather than from a feature list, so each one ends where the honest answer ends. Where the arithmetic cannot do something, it says so and tells you what to do instead; where a rule is a rule because an office wrote it down, the office and the wording are named.
What a passport desk, a state commission portal and a bank recruitment notice each mean by plain white, why the wall in your hallway is not it, and what to do when a checker refuses the very white you were told to use.
Read this before you resubmit anything.
A fringe of the old colour, a subject that floats above the ground it is standing on, light arriving from the wrong side, and an edge crisper than the lens ever was. Four giveaways, three of which have a control on the workbench.
Read this when something is off and you cannot name it.
Where the arithmetic stops. What a boundary can be recovered from when subject and ground are far apart in tone, what nothing recovers when they are close, and why a spectacle lens comes out as a solid shape.
Read this before you spend twenty minutes brushing.
The plan for this site lists five written pages. Two of them describe controls that have not shipped: bringing your own photograph in as a backdrop, and the difference between softening the room you were standing in and replacing it outright. Writing either one now would mean explaining a panel nobody can open, so they are held until the panel is there. What exists is written; what is written is true of the page as it is today.
Reading is optional. If the photograph in front of you just needs a different ground behind it, one of these three does that directly.
The image you open is read by this page and by nothing else — there is no server behind this domain that could receive it, and the outline is worked out by arithmetic running inside your own browser rather than by something your photo is handed to.