Frequently Asked Questions

Orsoni is an Italian smalti manufacturer, founded in 1888. Here is how they make the adhesive: Ingredients:

• 300g (10.6oz) of flour
• a spoonful of honey
• Half a spoonful of glycerine
• A spoonful of gum-arabic
• 1¾ litres (60 fl.oz.) water

Directions:

1. Put all the ingredients slowly into a large saucepan together, stirring until the mixture is even.
2. Simmer while you stir it slowly and continuously for about 45 minutes without ever allowing it to boil.
3. After turning off the heat, continue to stir it until it is completely cold in order to avoid hardening of the surface.

When complete, the mixture should have the same consistency as a sauce or mayonnaise. The glue can be laid on the sheet of paper/fabric with a brush, or you can add the glue to tesserae with a stick. You can always make smaller quantity with the same proportions mentioned above.

There is an excellent article by David M. Issitt that explains how coloured glass is made that explains this. Click here to read it.

Generally, grout will crack when there is too much water when you are mixing it together. The correct consistency for grout is to be thick, similar to peanut butter. (But don’t eat it.)

Yes, you can. Glass tiles are safe to use around a heat source such as a fireplace, but make sure that the binding materials (glue, grout, etc) are heat-resistant.

To use the basic nippers, place the blades perpendicularly on the tile; keep only 1/3 of the tile under the nipper and gently squeeze with consistent pressure at the end of the handles to get a sharp cut.

Wear eye protection, gloves, and when grouting, do so in a well-ventilated area. Do not allow unsupervised children to play in work areas, as there is a fair bit of glass debris.

Clean your work area frequently and choose a work surface that allows for easy cleanup of glass fragments and shards. Follow specific instructions from the manufacturer when using different tools and materials.

Contact a physician for further health information when dealing with compounds such as glue or grout.

It depends on the medium that you are working with. When using stone, marble and porous tiles, you definitely need to seal before grouting, otherwise group will permanently adhere to the tiles and dull the colours.

Glass tiles do not need to be sealed prior to grouting.

Use a soft cloth with a few drops of oil and gently rub the surface of your piece.

Paper mounts are only available with a special order and in large quantity. Please contact us for further information and minimum order requirements.

You can remove dried grout by covering it with a vinegar and water mixture for 5 minutes, and then scraping it off. Be careful to limit where you cover it, because this will soften any grout the mixture comes in contact with.

You can remove dried glue from tiles by rubbing it with acetone and a soft cloth. Be sure to do this in a well-ventilated area.

1. Apply adhesive to the textured side of the tile, and apply the tile to the desired location on the backing medium. While the adhesive is still wet, tiles can be easily moved for 5-7 minutes, at which time the adhesive will begin to set. Do not attempt to reposition tiles after the adhesive has set – if you need to remove a tile, you’ll need to use a hammer and chisel to carefully remove it, and this process may damage or crack the tile.
2. Once you have tiled the entire surface and the adhesive has cured for 5-6 hours, you can move on to the next step. If you are working with ceramic tile, marble or stone, we recommend sealing the tiles before grouting.
3. Apply mosaic grout into the grooves between the tiles. Be sure the grout is well worked into the spaces until the grout is level with the tile surface. Once you have grouted the entire piece, use a damp sponge to wipe off excess grout from the tiles. Make sure the sponge is damp, but not wet – if the sponge is too wet, it will damage the grout. You can rinse the grout off the sponge as necessary, but make sure you squeeze out most of the excess water before returning to your piece.
4. Allow the grout to dry. This can take anywhere from 30 minutes to several hours, depending on the grout that you are using.
5. Once the grout has fully dried, take a damp cloth and polish the surface of the tiles until it is free of grout residue. To protect your project, seal the entire surface with a sealing product.
6. Congratulations! Your mosaic project is complete.

Do not dispose of excess grout in the sink or toilet as it will damage your plumbing. It’s the equivalent of putting cement down the drain.

You can safely dispose of grout in the garbage. It is safe to wash utensils in the sink, provided that you have removed as much of the grout as you can from them prior to washing.

The Double Direct method is just like the direct method, except your tiles are adhered to a fiberglass mesh instead of directly to your substrate. Once the tiling is finished in this method, you can install it anywhere, be it a tabletop, kitchen backsplash or an outside mural.

Lay your design on a large flat area, cover it with clear plastic wrap, then lay a fiberglass mesh on top. Make sure that the design, plastic wrap and mesh is secured to the flat surface – if this moves during your mosaic, then your design will be shifted.

Using Weldbond glue, start adhering tiles to your design. Don’t use too much glue – instead, lightly dab the glue on the back of each piece. Follow your design that is under your mesh until completed. Beware of cutting your tiles over the mesh – you’ll end up with glass shards stuck in the grooves. When you’ve covered the entire mesh, allow the piece to set overnight.

Once everything’s set, carefully flip the entire piece over and remove the plastic wrap. The glue may still be wet at this point, but your tiles should stay in place. Allow time for the glue to finish drying.

If your mosaic is very large, you should cut it into workable pieces.

Mix your thinset (the adhesive that holds your tiles to the tabletop or wall) and apply a thin layer to the back of your tiles – this process is called buttering. Spread a thin layer onto the surface you’re applying your mosaic to and trowel through it until it is half the thickness of the tiles in your mosaic. Position your mosaic on the surface, and when you’re happy with the placement, apply pressure using a wood block or grout float. Allow the thinset to set overnight, and then grout as usual.

The Cut

The largest difference is the cut. Both techniques pour a puddle of molten glass – in Italy, it’s called a pizza; in Mexico, a tortilla. The Italian pizza is poured to a thickness of approximately 3/8″, and the tortilla to approximately 1/4″. The Italian smalti is poured thicker, then cut into thinner pieces to expose the inside of the pizza. The inside, or riven side, becomes the working surface of the material. By exposing the inside of the glass, you will see more vibrant, consistent and reflective colour. The pieces are more consistent in size on the visible working side but less consistent in thickness. Due to this variant thickness of Italian smalti, in order to have a finished project with a smooth surface, you will need to set the project in reverse. (The reverse method is only required if you wish to have a smooth finished project.)

Mexican smalti is cut larger, into irregular squares ranging from 1/2″ to 3/4″ on the visible working side with a fairly consistent 1/4″ thickness, which more resembles a piece of tile. The working surface of the Mexican smalti is either the top or bottom of the tortilla, and has a fairly smooth surface without bubbles. It can be set directly with or without grout, because of its smooth surface, consistent thickness and lack of bubbles. Many artists, including myself, will set the Mexican smalti on its edge if they are looking to add texture to their project.

The Colour

In Italy, they have been making smalti for centuries. Their focus in regard to smalti is on the purity, brilliance and consistency of the colours. To maintain these qualities, the smalti pots are changed regularly and great care is taken in not contaminating the colours. The recipes are handed down from generation to generation and the making of the smalti is as much an art as its final use.

Mexican smalti is young by comparison. It only came into existence in the 1950s, through collaboration between several Italian mosaic masters and a Mexican businessman. There was a huge demand to fabricate murals and other mosaic decoration in Mexico during this period, and combining Italian recipes and new cutting techniques, Mexican smalti was born. The direction of the “new” smalti material was to create a smooth surface with a hand-cut feel so they could fabricate murals and other public installations with a smooth surface. They blended the Italian recipes but poured them thinner so as not to waste the material, because they were using the outer surface, not the riven side. In doing this, they discovered the rich mottled beauty of the surface of the glass. Less focus was put on the recipes and pure colour, and more put on the mottled painterly look of the tortilla. Often, both sides of each piece will be a different colour and many different tones of the same colour will come from each batch of smalti.

Because the Mexicans are looking for the mottled colour, smalti pots are not changed regularly. When one colour is finished, a new colour is mixed and the two begin to blend, creating the mottled colour. As an artist and retailer of Mexican smalti, this is both a blessing and a curse – it makes for such beautiful colour variations in a single batch, but makes it more difficult to reproduce colours from one batch to the next. My advice when ordering Mexican smalti is to always order more than enough to finish your project as colours do vary.

Which should you use?

When deciding which to use for your particular project, it can be as simple as this: If you are doing an installation or require a smooth surface, it’s easier to do this with Mexican smalti. If you are looking for texture and reflectiveness, Italian smalti can’t be beat. Or – use both!

(This answer was based on a blog post by Kim Wozniak (USA).)

Emperor Diocletian, in the beginning of the third century, issued a decree establishing rates of pay for the various grades of mosaic artists. In 330AD, Emperor Constantine transferred the imperial seat from Rom to Byzantium and granted tax exemption to mosaic artists in order to encourage them. The technique of gilding tesserae was developed in the Byzantine era by applying a fine gold leaf to a sheet of plain or tinted glass approximately 8mm thick, covering it with a layer of powdered glass and then firing it. The resulting materials were ideal for producing colour effects because the unevenness of the powdered glass, and consequently of the overall thickness, created variations in tone and enabled gold to be used on very large areas. The popularity of mosaics began to decline in the 13th and 14th centuries, being superseded by painting on canvas and frescoes.