Apart from presenting the painting in an attractive manner, the frame is also intended to protect the painting from dirt and moisture that can be present in the atmosphere. It is important to remember that a painting should not be hung anywhere that would make it subject to direct sunlight, or major changes in humidity, such as a bathroom or kitchen environment. Even if a painting is painted on the most expensive watercolour paper, using the best quality paints, it would still not be able to stand up to those conditions for long before it either started to fade or become stained with mildew. So please choose your display area with this in mind. If the display area is a bright room or a room where artificial light is on for long periods, please consider using UltraViolet resistant glass if you value your collection. This will help prevent fading enormously.
The first thing you’ll need to know is what size of frame you will need? If you are planning to frame one of my 7 x 5 inch paintings yourself, using a ready made frame, I would recommend using an off-the-shelf 12 x 10 inch frame but please treat yourself to a professionally cut mount from a framing shop, it will only cost a couple of pounds and make all the difference to the way the picture will look. Personally, I would measure the painting and add 6 inches to both the height and width. E.g. If the visible area of the painting measured 7 x 5 inches then I would be looking to buy a 13 x 11 inch frame.
This would mean my painting would be mounted onto a mount board which is 13 x 11 inches but with a 7 x 5 inch bevelled aperture cut into it. The mount board has three functions. It prevents the artwork from making contact with the glass. It tidies the edges of the painting, and the painting can be mounted on it. I would recommend the use of an acid-free mount as this would not have a detrimental effect on the paper and is only fractionally more expensive. (If you are framing the painting yourself, any framing shop would be happy to cut and supply the mount to you).
Mount board is available in hundreds of colours but most artists tend to favour an ivory or off white colour. If you are in any doubt as to which colour you should use, play safe and use these colours. They will make the colours in the painting sing and complement virtually any colour scheme in your home. The painting is mounted onto the mount with the use of an acid-free water soluble gummed tape. Just use a couple of small pieces of tape and apply them as I have shown in the diagram. This will hold the painting in place on the mount but still allow the painting to expand and contract slightly due to small changes in the atmospheric humidity. If the painting was secured all round with tape, there is every chance the painting would cockle and look unsightly in a short period of time.
One last word of caution about cleaning. Do not spray glass cleaner directly onto the glass as some of it may find its way to the mount board by capillary action. It would only be a question of time before it then travelled towards the painting surface itself. Spray a small amount of glass cleaner onto a cloth, clean the glass and wipe off immediately.
Having followed these guidelines, you should be fairly confident in the knowledge that your grandchildren can look forward to receiving a family heirloom in a pristine condition.