The art of making exquisite glass mosaic tiles is simple! Let me show you. The purpose of sealing grouting is to make it waterproof and mildew-proof and to help prevent dirt. Many mosaic articles and books say that you have to seal the grout forever. I don\'t always agree. In my opinion, the interior wall Hanging mosaics displayed in a dry environment do not need to be sealed. I don\'t care at all because my indoor wall hanging won\'t get wet or dirty. However, indoor mosaics exposed to dirt and moisture (e. g. , Desktop and back) In fact, it should be sealed. Grouting on all outdoor mosaics should always be sealed to prevent dust and weather to the maximum extent. There are two basic types of grouting materials: 1) Penetrating power, 2) Membrane formation. Penetration Sealers: when the bottom liquid evaporates, these sealers soak in the mud and leave the deposit. Deposits, usually latex or silica gel, fill in the gaps in the grouting and then help the grouting to resist dirt, grease and liquid. The penetration sealing device usually does not change the color of the grouting unless it is slightly darker. High quality sealer usually reduce the color change of grouting. Membrane- Molding seals: These seals are not soaked in mud; Instead, they stay on the grouting surface and Harden, usually reaching a smooth surface (i. e. , They form a film on the grouting surface). Membrane- Molding capping agent is usually used in grouting dyes to deliberately change the color of grouting. Please note that the sealer does not provide 100% protection in all cases. Read the product label carefully under the \"limit\" title and you will notice that they usually say \"reject\" or \"resist\", which is different from \"providing complete protection. \"Do not expect the sealant to prevent dyeing in any case. I prefer to use a high quality penetration grouting sealing device on my glass mosaic. My favorite is the TileLab SurfaceGard penetration sealing material made of custom building products. It is water based, easy to use, easy to clean glass and remove dirt, water, oil and stains. I applied it to my mosaic desktop and trivets with a soft brush covering the entire surface. Two minutes later, when the sealer penetrated into the mud, I wiped the excess sealer from the glass tesserae with a paper towel. Then, after two minutes, I wiped off the remaining residue with a clean towel. If you wipe the Packer off the tesserae within a few minutes of applying it, there is usually no problem as it makes the glass dull or damaged. While two coats are recommended for the product label, I tested it and found that one coat is usually enough to accommodate my indoor mosaic desktop and trivets. When I first tried this product, I let the sealer dry for two hours and then dropped a drop of water on the grouting line. The water is not soaked in the inside but in bead shape, which indicates that the grouting has been fully sealed. So, my interior mosaic only uses a coating that requires stains and water resistance. However, I always wear two coats for all outdoor mosaics. It is important to erase the excess sealing material from the glass tesserae within a few minutes of applying. Do not take the risk of having the sealer blunt your glass with a residue that may not be removed if it is to be completely dried. In addition, do not forget to take appropriate safety precautions when using grouting sealant. Read and follow the product label. Keep in mind that making mosaic art is easy. You can do it. Yes, you can!