Sophia Othman

Mosaic art & Concrete Sculpture

Posts from the ‘Making Mosaic Art’ category

stained glass mosaic mural of phoenix plant leaves wild fire art expression regeneration after wild fire resurrection hope Visions of The Wild themed art
blue green iridescent stained glass for mosaic mural by sophia othman bay area mosaic artist

Iridescent Glass Tile in Blues and Greens

How to choose whether to go with glass or ceramic for mosaic? Mosaic artists have used just about any material for mosaics:  ceramic tile, glass tile, stone, shells, found objects, broken crockery, wood, metal.  And in mixed media mosaics, anything goes, with delightful results.  However, if you are choosing mosaic material for an outdoor art piece in a frost prone climate your choices start to narrow and both ceramic tile and glass tile can stand up to freezing if they are chosen carefully.

Is glass tile more colorful than ceramic tile?  Yes! the array of color available in stained glass sheets is dizzying and marvelous.  Most metropolitan areas have stained glass retailers so glass is easier to source in general.  Ceramic tile is available in a wide range of brilliant colors as well but is not nearly as nuanced in the variety available of any one color.   Daltile makes a colorful line.  McIntyre does as well.  Heath Ceramics in Marin county has rich color. Since most consumers don’t tile their kitchen or bathrooms or floor with bright yellow, red, and orange, the retailers don’t stock these colors and they must be obtained by special order.  To obtain brilliant colored ceramic tile can take up to 8 weeks lead time for the manufacturer to custom make the order and ship it.  Also the cost is higher as there are often one-case (12 square feet per case) minimums per color.  If I am designing a mosaic mural with many colors I would have to order a case of the colors of which I need a small amount.

Reflection & Glassy Shine & Iridescence

Ceramic tile with a virtuous glaze will have a shiny reflective look to it. Vitreous meaning glass. However, most ceramic tile will not look as shiny as glass. Matt ceramic tile is deliberately manufactured to achieve a less slippery surface when used in bathrooms and other flooring. Glass tile by definition will have a lot of reflectiveness and look aglow in certain angles and less shiny in others, giving it a dynamic changeability that is expected of glass tile.  Some ceramic tile is available with an iridescent sheen but stained glass and other glass shapes can come with stunningly beautiful iridescent coatings.  Your personal aesthetic and the purpose of the mosaic  will determine the degree of shine, glassiness, reflection, and friction that you want/need for the project.

stained glass mosaic mural of phoenix plant leaves wild fire art expression regeneration after wild fire resurrection hope Visions of The Wild themed art

Stained Glass Mosaic showing shiny reflective glass surfaces and iridescence

Is it easier to cut shape glass vs ceramic tile? Ceramic tile is usually twice as thick as glass used for mosaic. Most commercial ceramic tile used for mosaic is approximately 1/4 inches thick and most stained glass used for mosaic is 1/8th ” thick. Any thicker and they are prohibitive to cut and shape with reasonable ease. It is physically easier to cut glass than ceramic tile. However, to shape either ceramic or glass tile with precision takes skill and experience. Still, glass faster to shape & cut.

ceramic tile mosaic mural tree of life memorial mosaic

Memorial Mosaic Tree of Life Mural

There are many types of glass tesserae used for mosaic, pre-shaped pieces in circles, triangles, rectangles, teardrops, & etc. These come in thicknesses from 2mm to 7mm approximately. Most glass mosaic is made of glass pieces 3mm or 1/8th” thick. Glass tile is generally physically easier to cut and shape than ceramic tile. If you want to shape glass tiles precisely it is easiest to use stained glass. Stained glass comes in large sheets that can be cut into smaller and more precise shapes to do their duty in your mosaic art.

Mosaic Weight or Load on Architectural Support – Another consideration when choosing between ceramic tile and glass tile for mosaic is that the thinner glass will weigh less per square foot than the ceramic tile.

What is the purpose of the mosaic? Backsplashes, walls, murals, fine art mosaics, all these don’t have to withstand people walking on them, so they can be made of thinner and less durable tile. But for floor mosaics ceramic tile is the more durable choice. Ceramic tile that is high fired (harder) is necessary when creating floor mosaics due to the loads floors must support as we use them in daily life. Often higher fired ceramic tile has less vibrant colors are available at that higher kiln temperature. A high gloss finish is usually not desired as it also means less friction and a more slippery floor. So a more matte finish is desirable in floor mosaics that use ceramic tile. Ceramic tile can be manufactured with added grittiness to reduce risk of slipping. All these factors can combine to make the color and texture choices for ceramic tile for floor applications less vibrant and less reflective. That being said, I have seen spectacularly beautiful floor mosaics made with small glass squares called virtuous glass tile usually 3/4″ x 3/4″ x 3mm. The smaller shapes are less likely to break under normal load than longer pieces of glass. Insets of glass tile such as medallions or other shapes can add beauty to a floor without rendering the entire surface in glass and retaining the strength of ceramic tile for the rest of the floor.

What tile to choose for community built mosaics? Ceramic tile is the winner here, allowing individuals to shape, texture, and glaze individual tiles that can then be incorporated into a unified whole community mosaic art piece.  The image below shows a ceramic tile mosaic mural incorporating handmade tile from hundreds of students & staff at a K-8 school.  Each student created one tile.  The second graders created the poppies, the kindergartner’s and several older grades created the oak leaves, & etc.  Groups of students worked together to created the larger creatures like the hawk and deer.

handmade ceramic tile school mosaic mural installation images from beginning to finished product showing fiberglass mesh mosaic sections

School Mosaic Mural using Handmade Ceramic Tile

Glass is used in community art mosaic projects as well by allowing individuals to piece their own small mosaic to be incorporated into the mosaic mural or allowing groups to piece mosaic together. The difference I see is that shaping clay and coloring it with underglaze and glaze is usually an easier & more intuitive creative process when involving inexperienced participants in a community built mosaic mural. Handmade ceramics allow more line work and nuance and colors on each individual piece than pieced mosaic with glass tesserae. The image below shows stained glass mosaic marine creatures each pieced by a family group or a staff member from the school.  This image shows vitreous glass squares in the background of the mosaic in white and blue.

glass mosaic school mural art project stained glass mosaic vitreous glass mosaic group art community built art

Glass Mosaic Mural

These are only some of the practical considerations in choosing between glass and ceramic tile for mosaic.  There is no clear choice as it depends on your specific project’s practical needs and your aesthetic. Happy creating.

Photo by Mosaic artist Sophia Othman of her puppy in her studio Mosaic art San Francisco Bay Area
Art Studio’s Chief Morale Officer – Jasmine the puppy doing a superb “Down” on a kiln shelf

How do you prevent your ceramic wires from sticking to your kiln shelves? you use kiln wash – here’s how to make it yourself

Today I’m repairing, reshaping (with a tile wet saw), and reapplying kiln wash to my ceramic kiln shelves. Pleasant outdoor work on a bright winter day in service to my mosaic art studio. A lot of ongoing maintenance to keep my tools happy and show them love.

Basic Salt Kiln Wash Recipe
50% Alumina
50% Kaolin

To prepare your own kiln wash measure out a ratio of 1 to 1 of each ingredient and add water. Mix the kiln wash dry mixture with water thoroughly to the consistency of whole milk. To prepare your kiln shelf ,sand or grind your shelf as needed to remove flaky old kiln wash and wipe with a moist sponge to remove any loose flakes and dust. Then use a brush to apply a thin layer or two of kiln wash either in bare spots or covering the whole shelf.

These ingredients are very very cheap compared to buying premade Kiln wash and you can get them from any Ceramic supply store. My favorites in the bay area are Clay People in Richmond and Clay Planet in Sunnyvale. If you don’t want to do your own measuring you can buy dry pre-mixed kiln wash powder which is also much cheaper than buying prepared wet containers of kiln wash from the suppliers.

San Francisco bay area mosaic artist Sophia Hoffman prepares her own kiln wash for making handmade ceramic tiles for mosaic garden art bench
Raw Materials to make your own kiln wash

Even if you’re not interested in being frugal there’s a deeply enjoyable aspect to Diy in the art studio and it’s fun to know how to go from raw dry mineral ingredients to a product that matches a commercial kiln wash.

I laid down this kiln shelf separately so I would remember to add kiln wash to it. My puppy, Jasmine, is now eight months old. She can’t wait to grow up like all children saying that they their age is “5 1/2 “ years old – they are eager eager to go forward into life. Here if she is sitting on my kiln shelf saying to me, “ Mom I’m only half baked! “

Photo by Mosaic artist Sophia Othman of Handmade ceramic tile for mosaic art bench fired in ceramic kiln  in her studio Mosaic art San Francisco Bay Area
Handmade ceramic tiles On shelf protected by Kiln wash which is appearing as a bright white powdery surface on which the tile sit these tiles are for an art Mosaic bench with the most recent offerings from the Kiln

More DIY Kiln Wash :

If you want to get Uber geeky about kiln wash, here is a superb article in Ceramic Arts Monthly by John Britt that dives deeply into the topic and offers many recipe variations for specific applications.

Sophia Othman Bay area mosaic artist and concrete sculptor  applies underglaze and glaze glaze to handmade ceramic tile for garden art bench Mosaic of flowers bees and butterflies
Glazing handmade ceramic tiles to fire in the kiln

Today I am I’m in the blissful creative zone where time flies and every tiny task in my art studio (even tidying up and cleaning the tables) is a pleasure. Specifically, today I’m glazing tiles to get them ready to glaze fire.

After The handmade tiles are fired in the kiln the true colors show through.

 Glaze firing Photo of handmade ceramic tiles  by San Francisco bay area mosaic artist Sophia Othman
Just finished glaze firing the flower tiles
Sophia Othman Bay area mosaic artist and concrete sculptor  applies underglaze and glaze glaze to handmade ceramic tile for garden art bench Mosaic of flowers bees and butterflies
Yellow orange cone flowers and red handmade ceramic tiles destined to be part of a mosaic garden art bench

I have several projects that are billable and getting them done allows me to finish a commission and receive payment for it. Then I have many creative projects of my own that are incubating and are at various stages of doneness. Ranging from still being idea psychic babies and are merely thoughts in my head and some are at the stage of being on paper somewhere. Some at the stage of having the design drawn out enough that I can start creating it and some are at various stages of being done in terms of having an armature for a sculpture ready or having the tiles bisqued but not glazed for a mosaic mural, etc.

This is a mosaic garden art bench that I’ve been working on for a couple of years in my spare time. The bisque-fired handmaid tiles have been sitting in a box asking for attention – today I gave them some and they reward me with creative pleasure. I think the tiles at this stage look like cookies that are being frosted. The ceramic glaze and underglazes will start off being intensely colored when wet and then as they dry out they get powdery and pastel. So by the time they dry out they look like frosted cookies.

Sophia Othman Bay area mosaic artist and concrete sculptor  applies  glaze to handmade ceramic tile for garden art bench Mosaic of flowers bees and butterflies
Orange ceramic glaze in squeeze bottle Makes it easy to draw fine lines are using Ceramic at glaze

“Our Oak” Finally Installed

Oak Tree & Native California Animals School Mosaic Mural

Third Grade Students Work in Teams to Piece a Mosaic Mule Deer for School Mural

Well, it is finally up on the LRC (Learning Resource Center) wall!!  The Oak Tree of Life Mosaic Mural is installed and ready for students to come back to school in September and see their gorgeous and epic handiwork.  You can really see in the mosaic that an entire school participated in it’s creation.  The handmade ceramic tiles all look unique and you can tell each was the creative effort of one student.

Brief Backstory

The mosaic mural is a parting gift dedicated in honor of the school’s retiring Head Of School, Lucinda Lee Katz.  We estimate that over 600 students (Kindergarten to Eighth Grade) and staff were involved directly in the making of the mosaic.  The project started in December, 2017 and was permanently installed on a wall of the Learning Resource Center building (LRC) on August 2nd, 2018.    For more about how we designed the mosaic and which grades created which mosaic design elements read this post. 

Here are some photos from the installation process recently completed.  

Marin School Oak Tree Of Life Mosaic Mural Installed On Library Exterior Wall includes california native animals poppies butterflies mule deer doe fawns quail gray fox gray squirrel barn owl red tailed hawk opossum hare rabbit moths bees

Oak Tree California Native Animals Mosaic School Mural 10’x10’8″

Mosaic Mural Completed Installation in August 2018

These photos of the installation process showing the progression from bare cement board frame and how we install one mosaic fiberglass section at at time like a giant puzzle.  The metal frame and cement board backing was fabricated by Don Carlson, who has been incredibly supportive during the installation process.  


The Library building with the mosaic frame ready to go

A blank canvas ready for mosaic fiberglass sections. We are going to build a mosaic puzzle.

The first two mosaic sections are up!

The third mosaic section is up, only 31 more to go.

Notice that all three sections of the mosaic Mule Deer Doe are now installed.

The bottom third of the mosaic is installed.

This scaffold, loaned to us by Don Carlson, was essential to getting the job done.

Hanging around with an opossum halfway up a mosaic tree

The last two sections are left to be installed. I love the soaring red tailed hawk.

One last “keystone” fiberglass section to install with Carol Bevilacqua and Siram.

school mosaic mural installation images from beginning to finished product showing fiberglass mesh mosaic sections

The install team is tired but happy. Siram and Carol Bevilacqua helping. Grout is next!

school mosaic mural installation images from beginning to finished product showing fiberglass mesh mosaic sections

School Mosaic Mural Grouted – Install Completed – Library Building

school mosaic mural installation images from beginning to finished product showing fiberglass mesh mosaic sections

School Mosaic Mural Installation Process – Grouting All Done – One Happy Mosaic Artist!

Read more about the design process and our inspiration for this mosaic.


Installation team included Siram and Carol Bevilacqua.  Mosaic production assistance by Siram.  

Dragonflies have enchanted me all my life.  Their iridescent wings, their magical flight patterns, jagged, powerful for such a small creature, and yet still elegant.  They are formidable predators in the insect world, gorgeous yet deadly.  They eat mosquitoes so they are an important part of the natural abatement for mosquitoes and other flying biting insects we don’t find very beautiful.

The greens grays and browns of this garden mosaic rock seat blend gently with a natural setting.  The glass and iridescence add a touch of magic to the art piece.  The pebbles add a grounding element to the mosaic’s design.

My first degree is in Geology, i have a lifelong love of rocks and the natural world. I chose to decorate a natural rock with a mosaic that is an ode to dragonflies and their iridescent beauty.  I used glass tile in gentle green and gray and white colors, some with iridescence.  I chose a design mimicking the layering of sedimentary rocks and how animal fossils end up petrified in rocks.  The central green ceramic dragonfly was cut from a broken pottery plate i had been keeping to use in mosaic art.  It has finally found a home as a utilitarian geological mosaic art piece.  The rock serves as a soothing point of beauty in a garden and also as a small bench seat.

Mosaic Studio Tools

This rock weighed close to 200 pounds so i was able to work on it in my studio using a hydraulic heavy duty cart so.  This way i could stand comfortably while i pieced the mosaic.  A wet tile saw or ring saw is useful to make curved cuts in ceramic tile.




iridescent stained glass, vitreous glass, pebbles, shells, mirror, and small glass bead tesserae mimicking sedimentary rock layering.