PREPARATION
You will need:
* Pencil and paper
* Items to decorate
* Tiles
* Nippers/ light hammer and strong, clear plastic bag
* PVA glue and brush
* Grout
* Sponge
* Cloth
* Safety garments as applicable
You may choose to use small square craft tiles, made specifically for the purpose (usually from vitreous glass) and bought by the bag or tub. You cut them using a tool known as 'nippers'. This tool is used with a motion similar to the one made when cutting with scissors, and tiles can be nipped into halves and quarters - ideal for a geometric designs (see below), and eventually with practice, even into curves.
Alternatively, you can break up any leftover household tiles that you may come by or purchase cheaply (scrap stores sometimes have these in stock, and seconds are usually available from tile stockists). These tiles are broken up for mosaic use with a small, light hammer.
It's important, of course, to take the relevant steps to ensure safety before embarking on a mosaic project. Children and adults should wear goggles and a decorator's facemask when breaking up tiles prior to use, and should wear gloves whenever they are handling the cut tiles.
A good safety tip: put tiles inside a strong, clear plastic bag before lightly hammering them, in order to contain dust and shards.
It is essential to hammer lightly - you need pieces of tile big enough to work with at the end of the process! You should also ensure that you clear up carefully immediately after breaking tiles.
The amount of prior adult preparation and subsequent direct help required will, of course, depend on the children's abilities and experience.
Ordinary PVA glue can be used to stick tiles down, but you will need a non-toxic grout that is suitable for children to use in order to effectively seal the finished mosaic. (This is often available in the craft section of educational suppliers' catalogues as well as in some craft shops).
DESIGNS
Children start off by drawing out their design on paper. It's advisable to keep it simple and striking for the first experience of mosaic making.
Geometric designs and patterns are the easiest option if using craft tiles, as they won't need to be nipped into curved shapes. As a general rule, the smaller the item children are applying the mosaic to, the simpler the design will need to be.
Traditional picture mosaics have at least two sections, the focal point and the background (usually in contrasting colours), and they may also feature a border. Again, simple, bold designs look very striking. For a more adventurous twist, marbles and even shells can be incorporated into the design.
POSITIONING
Once a design is complete, it should be drawn directly on to the surface selected. (Use chalk if the pencil doesn't show up). From plenty of prepared pieces, children can begin to position the tiles, starting, if they have chosen a pictorial design, with the focal point, then the background, and finally the border. If the design features curves, some tiles may have to be cut as the children work.
Once children are happy with the placement of the tiles, they can stick the pieces into place one at a time, using PVA glue and a brush. If children are working collaboratively on a large project, this is something that will probably be completed over several sessions, so you'll need somewhere suitable to store the work in progress.
The glue should be given at least two hours to dry before the mosaic is grouted. Simply follow the manufacturer's directions - most grout comes with a spreading tool, and the method is the same as with household tiling.
Children should make sure the crevices are filled in well (for a good seal and to cover any sharp edges), and then wipe off any excess grout with a damp cloth. When the grout is dry, the mosaic can be polished.
ALTERNATIVES
There are various alternatives to using tiles to make a mosaic. Once a design has been created following the principles above, many general craft materials can be substituted. Tissue paper or cellophane can look particularly effective for instance.
If you plan to embark on a large tiled project, you should check that the design will look effective first, and give children an idea of what they're working towards. In this case, making a sample first in a simpler medium and on a smaller scale is definitely worthwhile.