Hardness, toughness and wear resistance are three separate properties. A specification that names only one of them protects against only one kind of damage.

A buyer asks whether a surface scratches easily. The answer comes back that it does not. Both parties consider the question answered, and neither has any idea what was just agreed.

Scratch resistance sounds like one property. It is at least three, measured by different tests, affected by different formulation choices, and traded against each other. A material can perform well on one and badly on another, which is why two products can both be described as scratch resistant and behave completely differently in the same room.

This article separates the properties, explains what each test observes, and sets out what can actually be written into a specification and checked on arrival. A related surface question, how a board ages outdoors, is covered in our piece on PVC board weathering.

The first thing to separate is the vocabulary, because the confusion in this subject is largely linguistic.

A fourth property belongs alongside these and is often merged into them. Impact resistance describes how a material behaves when struck, and it is the property that determines whether a surface chips or dents. A surface that has been made harder to resist scratching is usually more prone to chipping, which is the subject of section three.

One further distinction matters for the products in this range. A solid section and a foamed section behave differently under the same test, because a cellular core absorbs and distributes load in a way a solid one does not. The difference between the surface and the core of a board is covered in our guide to skin and core in PVC foam board.

Each of the three properties has a test, and each test has limits that determine what its result can be used for.

A point test, a drawn test and an abrasion test answer three different questions about the same surface.

The practical implication is that a single figure cannot describe a surface. Where a datasheet offers one number labelled hardness, it has chosen one of the properties and stayed silent about the others, and the two it has left out are often the ones that determine how the product behaves in use.

In a PVC compound the properties move against each other, and it is not possible to improve one without paying for it somewhere else.

The direction of the trade-off means the question is not how hard a surface can be made but where on the curve the application sits. A floor in a busy commercial entrance needs wear resistance above all. A wall panel that will be wiped clean needs scratch and chemical resistance. A board that will be handled and cut on site needs toughness, because it will be dropped.

Density deserves a note here because it appears in both directions. A higher density board has a denser skin, which reads as a harder surface, and it also has a more uniform core, which improves impact behaviour. For foam board, density is the closest thing to a single lever that improves several properties at once, which is why it dominates specification discussions. Its limits are discussed in our piece on why density is not strength.

When a buyer reports that a surface scratches, they are usually describing one of five distinct failures, and the remedy differs for each.

The practical value of the distinction is that four of these five failures are addressed by process and maintenance rather than by material selection. Protective pads on furniture feet, a specified cleaning method and felt glides under movable items between them prevent the majority of surface complaints, at no cost and with no change to the specification.

Flooring is where surface performance is specified most precisely, and it is also where the most confusion exists, because two different families of product use two different systems.

Laminate flooring is rated on a scale running from domestic light use up to heavy commercial, and those ratings derive from a combination of abrasion, impact and other tests applied to a laminate structure. The rating is a property of the whole assembly of decorative paper and resin layers, and it is meaningful for that product family.

For rigid core and vinyl plank the primary surface specification is the wear layer, which is a physical thickness of transparent material bonded over the decorative layer. It is measured in millimetres or in thousandths of an inch, and it is the number that determines how long the pattern survives foot traffic.

On a flooring plank the durability of the pattern is set by the thickness of the transparent layer above it, which is a dimension rather than a hardness claim.

The advantage of a wear layer specification over a hardness claim is that it is a physical measurement. It can be quoted in millimetres, it can be verified by examining a cross section, and it does not depend on operator technique or on which convention a laboratory follows.

What the wear layer does not control is indentation. A thick wear layer protects the pattern from being worn away, and does nothing to prevent a heavily loaded point from leaving a mark in the core beneath. That remains a question about the core material and its density, which is why two planks with identical wear layers can behave very differently under a piano leg. Where a damaged plank can be replaced rather than the whole floor, that is covered in our piece on repairing scratches and dents in rigid core flooring.

A surface specification that can be checked has four parts, and a claim without them is a description rather than a requirement.

The selection guidance for foam board surface characteristics sits alongside this, in our piece on the indicators that matter when selecting PVC foam board, which places surface behaviour in the context of the other properties a buyer has to balance.

Very little of this can be confirmed in a warehouse, and it is worth being clear about which parts can.

A comparison between two samples under identical conditions is informative. The same test on one sample in isolation is not.

The most productive approach is to combine the two. Use a comparative field test to narrow the field, then require a test report from the surviving suppliers, and check that the report names a method that matches the property the application actually needs.

The wider pattern mirrors every other subject in this group. A performance claim is only a specification when it names what was measured, how it was measured and what value counts as acceptable. Surface hardness is the clearest case of it, because the same word covers three different measurements and the choice between them determines which kind of damage the product will resist.