How the reading is produced

One narrow question: which regions of this sock have shifted away from white, and which way did the tone move. It answers with regions — toe, sole, heel, ribbed cuff, leg, whole sock — and with a direction for each: warm, neutral, chalky, or carrying a hue.

It is never asked what caused anything. The ranking of the four causes is arithmetic performed in your browser against a table of weights that is published on the front page and can be read line by line. If you disagree with a conclusion you can see exactly which observation moved it and by how much.

That split is the whole reliability argument of this service. A model that hands down a diagnosis cannot show its working. A table can.

No. It is an inference from how a fabric looks in a photograph. Nothing is measured, nothing is sampled and no reagent is involved. It reads distribution and tone, which is exactly what a person can be taught to read, and it is right about as often as a careful person with the same table would be.

Where you need certainty — because a garment matters, or because something is at stake beyond a pair of socks — a laboratory test of the fabric or a proper analysis of your water supply will tell you things this cannot.

Three things, and all three materially change the answer.

The hardness of your water

The single largest unknown. It varies street by street, and it decides whether mineral deposit belongs at the top of your list or nowhere on it. Your water company publishes the figure for your postcode, and looking it up will improve the reading more than any second photograph.

How much detergent actually went into the drum

Not the dose printed on the pack — the dose that went in, against the load size and the water. That is what determines whether residue is in play, and it is invisible in a photograph.

What has built up inside your machine

Detergent and conditioner accumulate in a drum over years and are redeposited on everything washed in it afterwards. A machine can be the cause of a problem that looks like a laundry habit.

A fourth thing sits alongside them: what has already been done to the sock. If chlorine bleach has been used on it, some of what you are looking at may already be permanent, and the service has no way of seeing that from the image.

All of this is printed on every reading, on every tier, outside the paywall and never behind a watermark.

No. Some of it cannot be recovered at all, and we say so.

Dye transfer generally cannot. Bound dye is colour in the fibre rather than a residue sitting on it, and there is no ordinary domestic step that reliably reverses it. Yellowing that has already been set by chlorine bleach generally cannot either: the bleach has reacted with what was in the yarn and driven the colour deeper, and that reaction does not run backwards.

Where that is the position, the reading states it and moves to limiting the damage and preventing a repeat. It does not offer another cycle to try. This service does not tell anyone that a few more washes will sort it out, and it does not promise that anything will definitely come back. A false hope here costs you a fortnight, the fabric’s remaining life, and the chance to protect the whites you still have.

The section headed what would make this worse. It is shown before the result on every reading, it has no close button, and it is free on every tier.

The reason it comes first is that most people arrive having already tried bleach or a hotter wash. For most of the causes here, those two are not merely ineffective — they fix the discoloration in place permanently. Chlorine bleach reacts with oxidised skin oil and drives the yellow deeper. Heat sets that same yellow and drives more mineral out of hard water onto the yarn. Doing either before you know which cause you have is the single most common way a recoverable sock becomes a permanent one.

This service recommends no detergent, bleach, water softener or whitener by brand or by product, and never will. Where a treatment step needs one, it names a generic category — an enzyme-containing detergent, a water-softening agent — and stops there. Which one you buy is your business and we have no stake in it.

It also uses no household remedy of the unverified kind that circulates online. Those mixtures are not a shortcut around not knowing the cause, several of them make specific causes worse, and none of them belongs in an ordered treatment that claims to know why it is ordered that way.

No. This service evaluates no brand and reaches no conclusion about the quality of any product.

The four causes it distinguishes all sit on the use and laundering side: skin oil left in the fibre, detergent that was not rinsed out, mineral from the water supply, and colour released by something else in the same drum. None of them is a statement about how a garment was made, and treating one as though it were would be both inaccurate and unfair to whoever made it.

Any brand name visible in a photograph you upload is masked before that photograph appears in an annotated view, on the wall of examples, in anything shareable or in a social image. The masking is not a setting.

For the same reason, the terms of service expressly prohibit using a reading as evidence in a return, a complaint, a warranty claim, a chargeback or any assertion about the quality of a product. It is not capable of supporting one.

Anything where a wrong answer harms someone. Specifically, this service must not be used for or in connection with:

• medical diagnosis, treatment or any decision about health;
• legal advice or the conduct of legal proceedings;
• financial or insurance decisions;
• safety-critical systems of any kind;
• decisions affecting employment, credit, housing or access to justice, whether about yourself or about anyone else.

It reads discoloration in knitted fabric. That is the whole of its competence.

No. Everything on this page is about the accuracy of an assessment — how confident you should be in a ranking drawn from a photograph. It is not, and may not be read as, an exclusion or restriction of your rights in respect of the service itself.

Under Chapter 3 of Part 1 of the Consumer Rights Act 2015 digital content supplied to a consumer must be of satisfactory quality, fit for any particular purpose you made known, and as described. Section 47 prevents a contract term from excluding or limiting those rights, and we do not attempt to. Nothing in these terms affects your statutory rights.

support@simplyhosieryonline.shop, with the reading if you still have it. Every report is read by a person. The table the ranking runs against is a published document and it changes when it turns out to be wrong — which is the point of publishing it.