For full and current technical specifications please refer to the makers web sites: (search Colourmount or Arquadia or Timecare), and if in doubt about the suitability of any board please seek advice.

Mount Board Specification

What do conservation, standard, and acid-free white core mean? And what is Museum board?

There are different types of board we can cut mounts from. Specifications differ between manufacturers but for the sake of simplicity we have divided these into these main categories of board; "Standard" and "Conservation/Acid Free", plus Museum.


Standard board

1250/1300 micron

  Conservation / Acid Free

1400 micron

  TimeCare Museum

1650 micron

The mounts we sell in our standard (budget) board category are neutral ph, as are the more expensive black-core, and the board is made by Slater-Harrison Colourmount.

These boards usually have a cream/off-white core (the part you see in the bevel) and this category also includes boards with a solid black or coloured core.

Suitable where economy is important. 

This is our "budget" board.  1200 to 1250 micron thickness (1.2 to 1.25 mm)

Summary: Where price is the main issue choose this option. Low cost, suitable for resellers and volume buyers, saves money, does a basic job at a low price.


Makers and trade organisations change/update their standards and definitions of what is "conservation" and what isn't from time to time. If you are not sure, these guidelines will give you a good idea which type of board you might need. If in doubt opt for acid free/conservation.

The reason there is a disclaimer below is because I seemed to be having to re-write mountboard specifications  every fortnight to keep the description  accurate each and every time one or another manufacturer changed their idea on what was, or wasn't "conservation" board. Often because of the latest whim of the fine art trade guild.


For full and current technical specifications please refer to the makers web sites: (search Colourmount, Timecare and Arquadia), and if in doubt about the suitability of any board please seek independent advice.

Exact colour matches can change slightly from batch to batch.

  The mounts we sell in the conservation/white core category are acid-free and the board we use for these is mostly made by Arquadia.

The term "conservation" refers to the protection the board offers the artwork. Also see environmental info

Dark colours may be called "acid free white core" board,  and the paler colours will usually be called "white core conservation" by the makers.

Both of these have a white core, just like it says on the tin, and are slightly thicker than standard mounts (1400 micron).

They are essentially the same but the face papers (the part not in contact with the art anyway) may have different fade or bleed properties - so we have placed them in the same "acid-free/conservation" category to keep it simple.

Summary:  Will offer some degree of protection for the artwork when framed, so if in doubt choose this option. (For valuable or precious items, seek advice)

Arqadia boards: PEFC (Programme for the Endorsement of Forest Certification schemes) and FSC (Forest Stewardship Council) Chain of Custody accreditations from BM TRADA Certification Ltd. These schemes provide assurance mechanisms to purchasers of wood and paper products that they are purchasing wood produced in a sustainable way.

More info

Conservation and Whitecore Specification (quoted from Arquadia, 2012)

The surface and backing papers

  • Made from chemically-treated pulp using pH sizing and lignin-free, except for Metallics which are not acid-free.
  • Blue wool scale (BWS) minimum rating 3+
  • Individual BWS ratings are marked on the reverse side of every sheet.
  • Buffered with calcium carbonate.*
  • The water-soluble extracts are minimal i.e. chloride below 0.05%, sulphate below 0.25%. For extra defence it contains a buffer of calcium carbonate to guard against contamination by air-borne acid for the life of the board.

The Core

  • High-quality alpha cellulose. Lignin-free and bright white throughout.
  • Buffered with calcium carbonate.*
  • Passes the Silver Tarnish Test and Photographic Activity Test.

The adhesive

  • Aqeous PVA with neutral pH.
  • Buffered with calcium carbonate.*
  • Is plasticiser-free.

* Minimum 3% by weight

Accelerated ageing test
TAPPI T.509 SU68
Unaged - pH8.9
100 -pH8.9
200 -pH8.9
300 -pH8.9


Timecare: Maximum protection. Designed for conservation, this 100% Cotton Museum Board has set the standard for the highest specification of Museum mounting since the early 1980’s and from that time has been the board of choice for major museums in Great Britain and Europe, and Timecare also has a Royal Warrant.

Cotton is almost 100% pure alpha cellulose and therefore requires less processing than wood sourced fibres. Specified by the founder of Conservation By Design it was the World’s first board to be laminated with EVA plasticiser-free adhesive which is more resistant to acid hydrolysis than other cheaper synthetic adhesives. This is important if you are looking for the maximum level of protection because if the adhesive breaks down and ‘off gases’ in the micro-environment of a frame or a box the object enclosed may be damaged. The board passes the PAT and Silver Tarnish tests and is therefore suitable for all media including photographs. This board combines the utmost purity with excellent cutting and erasion properties.

Used also by textile conservators for the mounting and storage of wool and silk.

Although timecare is available in thinner specification, we normally use the 1650 micron thicker board.