All framing materials must be stored in a controlled environment where the humidity ranges only between 45% and 55% and the temperature is maintained between 15°C and 26°C (approximately 59°F to 79°F).


It is of the utmost importance that the work of art and all framing materials be dry and remain in this relative humidity and temperature during framing. To provide further protection against the growth of mould after framing a fungicide treatment is recommended just prior to the actual framing.


The framing area must be clean and the air filtered to ensure that no dust, bacteria, etc. be trapped within the frame.





Only glass (crystal clear) or acrylic sheeting should be used as glazing material. Acrylic sheeting should not be used on pastel or charcoal drawings. Under no circumstances should the artwork be allowed to touch the back of the glazing material. As there is little possibility of any moisture or condensation forming on the inside of acrylic sheeting, an acrylic 'sandwich' frame is reasonably safe. However, only 100% ragboard should come into contact with artwork of value, never the glazing material. There must be sufficient clearance between the framed piece and the back of the glazing material to allow for the possible expansion of the work of art without it touching the glazing material.





The rabbet (inside edge) of wooden frame mouldings should be sealed with a clear acrylic sealer as a barrier against the acidity of unfinished or unsealed wood.




Only mulberry paper or other suitable Japanese papers, hand-torn not cut to the appropriate size for the work of art, should be used for mounting hinges. The tearing by hand ensures that there are no hard edges on the hinging paper that could leave pressure marks on the artwork.


These hinges should be attached to the back of the artwork with properly prepared rice or wheat starch glue that is pH neutral. A fungicide added to the glue ensures that mould will not grow from the moisture in the water-based adhesive. For the future removal of the artwork from its mount and hinges, the glue must be water-reversible without leaving any residue. 


The paper used for hinging should not be stronger than the paper mounted. Hinging material must only be strong enough to hold the artwork in position. If it is stronger than the paper it supports, it can cause it to tear at the mounting points if the framed picture falls, is dropped or receives rough handling during packing and shipping. In the case of a shock the hinging material should give, thus avoiding any damage to the work of art.





Overmatting (Window Mount)

 Any overmat that touches the print must be of 100% ragboard and, preferably, 4-ply in thickness. If a hand-coloured beveled edge is used the colour must be sealed with a proper clear acrylic sealer.


If any additional coloured matting is used, it must always be backed with a 100% ragbord mat that extends a minimum of 1/4" towards the artwork on all sides from the coloured matboard. The beveled edges of any coloured matboard should be sealed with a clear acrylic sealer.


So-called 'acid-free' matboard cannot be used for framing to museum standards. This is only normal wood-pulp matboard that has been buffered, generally with calcium carbonate, to neutralize its acidity. It will, in time, damage the work of art. Buffered matboards should NEVER be used with alkaline-sensitive articles or certain types of photographs. Only 100% ragboard should come into contact with the art in front (overmat) or behind (undermat).

Fabric-Covered Mats - Only 100% cotton or 100% linen should be used and the fabric must be mounted onto the 100% ragboard with rice or wheat starch glue that has been treated with a fungicide. It is preferable, when using fabric-covered mats, that a 100% ragboard mat be used behind the fabric mat for complete protection, although aesthetics sometimes prevent this. The use of fabric other than 100% cotton or linen requires a backing mat of 100% ragboard as a barrier between the artwork and the fabric-covered mats.



Undermatting (No Window Mount)

Any undermatting must be of 100% ragboard and should be 4-ply in thickness.

Fabric-Covered Undermat - Only 100% cotton or 100% linen should be used and the fabric must be mounted onto 100% ragboard with rice or wheat starch glue that has been treated with a fungicide.


When framing works of art with an undermat, a spacer of 100% ragboard (or 100% ragboard covered with the same fabric as the undermat) must be used to keep it from touching the back of the glass. The spacer should be of sufficient depth to ensure the artwork does not touch the glazing material even if minor waving occurs.


For mounting works of art where the paper is not of sufficient weight to hold the piece against the undermat, it may be necessary to add more hinges at the sides and bottom edge. These should be kept to a minimum. A mounted work of art on paper must be allowed to expand and contract and should never be expected to lie perfectly flat against an undermat. An excess of hinging or improper mounting can cause the paper to tear during an extreme change in environmental conditions.




In assembling the mounted artwork with the glass or acrylic, a pH neutral tape should be used to seal the edges from the front edge of the glazing to the back edge of the 100% ragboard backing mat, creating a 'sandwich'. This will not guarantee that moisture will not enter this area if the piece is kept in a very humid environment, but it will eliminate the possibility of dust or dirt getting in. As dust and dirt are major contributors to the growth of mould on paper, the 'sandwich' assists in the prevention of this common problem.




After the 'sandwich' of glazing, matting and artwork has been placed into the frame, an identically-sized piece of acid-free foamcore board must be used as backing. This helps to strengthen the framed artwork and forms an additional barrier against moisture. The backing should be securely taped with acid-free tape to prevent moisture from entering at the edges of the backing and the inside of the moulding. In very large works of art it may be preferable to use a wooden strainer or even a sheet of plywood to give sufficient support and prevent any twisting of the frame. If a wooden strainer or plywood is used the inside surfaces must be treated with a clear acrylic sealer.


After a suitable backing is added, a sheet of clear PVC is used to cover the entire back of the framed piece. This sheet is mounted to the back of the wooden frame either by taping or gluing. Tape is preferable as the PVC sheeting acts as a further barrier against moisture and, if a water-based glue is used, some moisture could be trapped inside this barrier.


To finish the back of the frame, a dust-cover is attached. We prefer to use a black kraft paper taped to the back edge of the wooden frame. The colour black allows the collector to see quite easily when any dust or even mould appears on the back of the framed picture due to damp walls or rooms.

In finishing the framed artwork, a wire of suitable strength and the two mounting points to hold this wire is positioned. Mirror hangers should be used on large, heavy pieces. The best wire is braided brass coated with PVC. Fittings holding the wire to the picture should be mounted into the back of the frame or, if the frame moulding is too narrow, into the back of the strainer or plywood backing. The screw-eye type of fitting should never be used, as this is easily pulled out of the frame.


Soft plastic or rubber bumpers should be attached to the bottom corners. These not only help to keep walls from being scratched and keep the pictures straight on the walls, but, more importantly, ensure that air can circulate behind the frame, helping to prevent the growth of mould. The bumpers must, however, be of sufficient thickness to be of use: small flat stick-ons do not help.





Particular care should be taken when cleaning the glass that not too much cleaner is sprayed on directly as it may run into the area between the glass and the frame. To be safe, spray a soft cloth or paper towel with the cleaner instead. To clean acrylic glazing it is preferable to use a professional acrylic-cleaning product as others, containing ammonia, can damage acrylic sheeting. Professional acrylic cleaners also contain an antistatic ingredient that helps to prevent lint and dust adhering to the surface. Galerie du Monde can provide an excellent acrylic cleaner, which is also an antistatic treatment. Only very soft paper towelling or toilet tissue should be used when cleaning acrylic to avoid hairline scratching.


Framed works of art should be taken off the wall every couple of months and their backs dusted with a dry cloth. The wall area should also be carefully dusted. If its black backing paper shows any sign of moisture the picture should be regularly checked to ensure that mould is not starting to form due to a damp wall or humid room. Once the backing shows signs of considerable dampness and the artwork starts to buckle, it should be returned to the framer to be opened. All inner materials and the work of art should be dried and treated with a fungicide and properly returned to the frame. This may happen in newly constructed buildings where the concrete walls are still extremely damp or in homes and buildings where insufficient care is taken to ensure that humidity and temperature, especially during Hong Kong's summer months, are not excessive.


Framed works of art should not be hung in direct sunlight. Other than moisture, sunlight is the most active and insidious enemy of works on paper. Should the collector find it impossible to hang the picture on a wall that is not exposed to direct sunlight, then a cloth should be hung over it during the hours when direct sunlight would shine on it. However, framed pictures should not be kept in closets or stored in dark areas either, as, linked with other factors such as humidity, inadequate ventilation, etc., this creates conditions in which micro-organisms, insects and rodents can develop and thrive.


As it may be impossible for the collector to ensure that his framer has complied with all the above, the following RULES should be followed by any framer who offers Conservation Framing to Museum Standards to his customers.


ALWAYS make the frame large enough to hold the artwork.

NEVER cut or fold artwork to fit a frame.

ALWAYS use at least 4-ply 100% pure ragboard in front of and behind the piece.

NEVER allow the wood of the frame or wood-pulp board to come into contact with the picture.

ALWAYS hinge-mount, using mulberry paper hinges and vegetable starch glue.

NEVER wet or dry mount.

NEVER use hinges that are stronger than the paper being mounted.

NEVER use glues that are not reversible with water or that contain impurities.

ALWAYS leave a space between the artwork and the glass.

NEVER allow the work of art to come into contact with the glass.


A little care and attention to your framed works of art will ensure their preservation and retention of value for generations to come.