---
title: "What is a MDF made of?"
description: "Wood pulled apart into individual fibres, mixed with resin and wax, and pressed hot into a board. Every component, the material it uses, and the constraint that made"
url: https://atoneplace.net/made-of/mdf/
site: "At One Place"
---

# What is a MDF made of?

**What is a MDF made of?: Wood pulled apart into individual fibres, mixed with resin and wax, and pressed hot into a board.**

MDF has no grain, so it routs and moulds cleanly in any direction and takes paint better than any solid timber — which is exactly why skirting, architrave and painted doors are made from it. The same absence of grain means an edge has nothing for a screw thread to grip, so screws must have a pilot hole and should not be relied on in the edge of a board at all. The serious point is dust: machining MDF produces very fine wood dust carrying resin, hardwood and softwood dust are classified as carcinogenic to humans, and cutting a sheet without extraction and a properly fitted mask is genuinely worth avoiding. Water swells it irreversibly, so a soaked MDF panel never recovers.

## Component by component

*Every material is a choice, and the third column is the constraint that drove it.*

| Part | Material | Why that material |
| --- | --- | --- |
| fibre | softwood chips steamed and torn into fibres in a refiner | Working at fibre level rather than chip level is what gives MDF a completely uniform, grainless body that machines like a solid. |
| resin | urea-formaldehyde, or melamine-urea-formaldehyde in moisture-resistant grades | It cures under heat in the press in minutes; the melamine version resists hydrolysis, which is why MR board survives a kitchen. |
| wax | paraffin wax emulsion, around 1% | It slows water absorption at the surface, though it does nothing about the swelling that soaks a cut edge. |
| density | pressed to roughly 600-800 kg/m³ | That is denser than most of the softwood it is made from, which is why MDF sheets are so much heavier than they look. |

## Other building materials objects

- [Glass](https://atoneplace.net/made-of/glass/) — Sand melted with soda ash and limestone — three cheap minerals, floated flat on molten tin.
- [Concrete](https://atoneplace.net/made-of/concrete/) — Stone and sand glued by cement paste — and it hardens by a chemical reaction with water, not by drying.
- [Road asphalt](https://atoneplace.net/made-of/asphalt/) — About 95% crushed stone and sand, glued together by roughly 5% bitumen from the bottom of an oil refinery.
- [Brick](https://atoneplace.net/made-of/brick/) — Clay and shale moulded and fired until the particles partly fuse — a manufactured rock.
- [Mirror](https://atoneplace.net/made-of/mirror/) — A sheet of ordinary glass with a microscopically thin silver layer on the back, sealed under paint.
- [Plywood](https://atoneplace.net/made-of/plywood/) — Thin wood veneers glued in alternating grain directions — the cross-lamination is the entire idea.

## Common questions

### What is a MDF made of?

Wood pulled apart into individual fibres, mixed with resin and wax, and pressed hot into a board.

### What is the fibre of a MDF made of?

Softwood chips steamed and torn into fibres in a refiner. Working at fibre level rather than chip level is what gives MDF a completely uniform, grainless body that machines like a solid.

### What is the resin of a MDF made of?

Urea-formaldehyde, or melamine-urea-formaldehyde in moisture-resistant grades. It cures under heat in the press in minutes; the melamine version resists hydrolysis, which is why MR board survives a kitchen.

## Related pages

- [Glass](https://atoneplace.net/made-of/glass/)
- [Concrete](https://atoneplace.net/made-of/concrete/)
- [Road asphalt](https://atoneplace.net/made-of/asphalt/)
- [Brick](https://atoneplace.net/made-of/brick/)
- [Mirror](https://atoneplace.net/made-of/mirror/)
- [Plywood](https://atoneplace.net/made-of/plywood/)
- [Pencil](https://atoneplace.net/made-of/pencil/)
- [Tennis ball](https://atoneplace.net/made-of/tennis-ball/)
- [Banknote](https://atoneplace.net/made-of/banknote/)
- [Golf ball](https://atoneplace.net/made-of/golf-ball/)
- [Paper](https://atoneplace.net/made-of/paper/)
- [Soccer ball](https://atoneplace.net/made-of/soccer-ball/)

## Sources

- Typical range compiled from manufacturer specifications — At One Place (/about/)