Glass Clay, a Step by Step Tutorial using Steider Studios Glass Medium

May 28, 2010

Effective 4.1.15 this part of my business is closed.  I have sold the last of SSGM and it is no longer available. Thank you so much for supporting my efforts all these years.

I’ve been asked often lately about making glass clay (glass paste), so thought I’d give you a quick review:  what it is and how I make it.  I’ve taught this technique nationally since 2004, at the Art Glass Association Conference in Portland Oregon.  This is the first year in the last six that I did not teach Glass Clay (or Pate de Verre Without Molds) at the Las Vegas Glass Craft & Bead Expo!

Essentially glass clay is glass paste, another form of Pâte de Verre, but without having to make molds.  Certainly not a traditional technique, but a fun, easy, fast way to make small glass sculptures, buttons, beads, and more!

I make a clay-like substance, glass paste, by mixing powdered glass with a liquid binder or medium.  I prefer to use Steider Studios Glass Medium™.  After testing many different materials my new Medium burns out cleaner than anything I’ve ever tried, while still being able to carve more detail into it after it’s dry and before firing.  Most people use CMC, and I’ve heard of and tested many other concoctions that may or may not work for you, but rather than go into them all I’m going to just tell you how I make it, using the best Medium I’ve ever tried.

I mix Steider Studios Glass Medium™ with room temperature or warm tap water (if your water contains heavy mineral deposits, you can use distilled water, but it takes longer to set up…as long as a couple of days!):  Fill a clean jar with a cup of water.  Sprinkle in one teaspoon of Medium for a very thick paste.  (If you live in higher elevations, you’ll need two teaspoons.)

Use a whisk or fork to stir until dissolved, then let stand 30 to 60 minutes to thicken, stirring occasionally.    I like it to be the consistency of jelly.  I have stored Steider Studios Glass Medium™ in my studio for over two years after mixing, but typically it’s used up within a week.  I have used other binders that developed mold and just so you know, the mold adds an interesting patina.  If you prefer a less gelatinous mix, by all means thin it with a little more water.  Also, if you’re planning to use it for liquid lines, you’ll want to dilute it.

Wearing a respirator or N95 disposable particulate mask, place your glass powder into a mixing bowl.  I prefer to use a small glass bowl, but often use a 4 or 8 ounce plastic food storage bowl.  Ratios of glass powder to Medium vary, depending on the powder.  Straight out of the jar glass powder can be as grainy as sand or as powdery as talc.

As a starting point I use 2:1, glass to Medium.  I’ll place 2 heaping spoonfuls of glass powder into my bowl, then drizzle 1 heaping spoonful of Steider Studios Glass Medium™ over the powder.

Using a palette knife or spoon mix well, mashing Steider Studios Glass Medium™ into the glass powder until it’s glossy.  It should be the consistency of cookie dough, or a wet pie crust, holding together when pinched or rolled into a ball.  If it’s too dry, your project will crack; add more medium a couple drops at a time.  If it’s too wet, your project will sink down into itself; sprinkle more powder into the mix, a little at a time, mixing well after each addition.

Once it’s mixed to a consistency that feels like clay or cookie dough you’re ready to play.  You have about 30 minutes working time to sculpt it, make pattern bars or press it into candy molds to freeze, then it begins to dry out.

I mix all my colors  before beginning to sculpt, and wrap each with plastic wrap to keep it wet until I’m ready to work.  I can store glass clay like this for weeks and have left it for up to a year.  It can be a bit sticky, so I work on top of waxed paper to stay as mess-free as possible.

For sculpting I use dental tools, metal and plastic sculpting tools, plastic make-up applicators, toothpicks, kitchen implements and whatever happens to be close at hand.

I’ve made faces, flowers, animals, and small open vessels and bowls.  These small sculptures can be used for door pulls, plant and garden decor, adornment for lidded boxes and much more.

You can press glass clay into candy molds, freeze for an hour or two, then pop it out of the molds.  The advantage to using Steider Studios Glass Medium™ for this application (known as ‘freeze and fuse’), is you can ‘cold work’ the edges and carve in additional detail before firing, after the piece is completely dry.

One of my favorite ways of working with glass clay is making paste pattern bars.  Have you played with polymer clay?  Play dough?  I use the same principles.

Roll it out (or roll it through a pasta machine) between sheets of waxed paper & stack layers of different colors, then slice, re-stack and slice again.

It’s easiest if you roll between two pieces of waxed paper because it can be sticky.

Make what I fondly call ‘Pig in a Blanket’ by making a rope, then wrapping it with a different colored ‘blanket’ that’s been rolled out flat.  Or roll your pigs into many blankets for ‘rings’ of color when you slice.

Pattern bars are sliced with a tissue slicing blade, rolling the bar one quarter turn after each slice so you don’t end up with one flat side.  Use these slices for buttons, beads, cabochons, or as decor for other glass projects just to give you a few ideas.

Make coils or ropes of clay, place different colored ropes next to each other for millefiore.

More food for thought:  add mica!  A little mica goes a long way.   Adorn with dicro slide!  Use a cute scrap-booking punch to cut shapes from Dicro Slide that enhance your design and apply just before firing.

To get a spiral effect, stack rolled out sections on top of each other.

Carefully peel off the wax paper, keeping it close to your work surface.

Then roll it up, smooth out and slice.  The ends will be uneven unless you roll out rectangular shapes instead of ovals.  I slice off the ends, roll them into balls, pushing the colors into a marbled pattern, then flatten them for buttons and cabs.

The next step is to let your projects dry on paper towels.  Use a food dehydrator, or just set them aside for a few days.  In a one day workshop we use hair dryers to speed the drying process.  Once dry, glass clay is very fragile, like a meringue cookie so use care in handling it.  Gently peel off the paper towel from the bottom.  Using an emery board and wearing your respirator, file off any rough edges along the bottom.  Use a wooden skewer to sand off any rough spots in your details.  You can use a skewer or a dental tool to carve in additional lines if desired.  Just remember to take care as it’s fragile.  Did I already say it’s fragile?  It’s very fragile!

When you’re ready to fire, try to fire like sizes and like colors together.  For larger projects or light colors, your soak time will be slightly longer.  I strongly recommend using a kiln that you can watch the progress so you’ll know when to stop and anneal, and you can note the process temperature in your kiln.  Your pieces are going to shrink approximately 25 to 30%, depending on your process temperature.  The longer you soak at process temperature, the glossier they’ll get and the more they’ll shrink.  Vent your kiln until it reaches 1000º while the binder is burning out.  You can ramp up AFAP, but I think it’s better to control the ramp up; and do start peeking around 1200º to 1250º.  Be sure to wear your safety glasses when looking inside the heated kiln.  In my kiln, depending on the size and color, my process temperature is 1300º with a 30 minute soak for small two to three-inch sculptures; or 1350º with a 13 minute soak for beads and buttons.  I anneal at 900º, using Bullseye’s annealing_thick_slabs chart for thickness.

I love introducing people to working with glass powders, whether wet or dry.

I hope you found this post useful.

Have Fun!  Be safe, wear that respirator and don’t forget your safety glasses!!

Effective 4.1.15 this part of my business is closed.  I have sold the last of SSGM and will not be re-ordering supplies.  Thank you so much for supporting my efforts all these years.

46 Responses to “Glass Clay, a Step by Step Tutorial using Steider Studios Glass Medium”

  1. Shirley Jones Says:

    Linda, I love your explanation and pictures of your new medium! Very thorough and enticing!
    I feel very fortunate to be able to try it before you can buy it! You can count on me as a customer! Wishing you the best!


  2. Toni Says:

    A most excellent tutorial, Linda!


  3. Thanks Toni! Always appreciate your kind words.


  4. Shirley, you are so sweet, I hope you like my Medium!


  5. Gabe Says:


    I love your tutorial. Great job! Really looking forward to trying your new medium. Thanks for posting this tute.




  6. Terri Johanson Says:

    Great job Linda…your new medium sounds great!


  7. Thank you Terri!!


  8. Sarah Tippit Says:

    Chomping at the bit! Can’t wait to try it out! Congratulations on all the hard work finally coming to fruition! Sarah


  9. Thanks for the support Sarah!


  10. Sylvanye Says:

    FANTASTIC, can’t wait until to start shipping the new binder, remember just ship and charge me — by the way the seaweed was great to work with too.



  11. Thanks Sam, will do!!


  12. Marie Ricci Says:

    Great tutorial, Linda. I can’t wait to get my hands on your new binder.


  13. Thanks Marie! Soon!!


  14. Chandru Kalro Says:

    Great tutorial Linda. Cant wait to try it out!


  15. A Simmons Says:

    Thank you for being generous and sharing this with us. I can’t wait to play!!


  16. Wow! Not only are you a gifted glass artist….you are part scientist too! Awesome Linda. I hope this is a great success for you.


  17. Kathleen, you’re too kind. Thank you!


  18. Nikki O'Neill Says:

    Looking foreward to trying it out!


  19. I think I’m just waiting on the labels now, it should be out soon!


  20. Thank you for taking the time to share your most excellent tutorial with us!




  21. You’re welcome!


  22. Robin g Says:

    I will be one to try it also..can’t wait I have lots of ideas.


  23. I can’t wait to see what everyone does with it!! I’m trying to stay patient while awaiting all the final steps….


  24. Is the medium available, where do we order it. thank.s


  25. Yes, it’s available! My web designer is installing a shopping cart at Steider Studios.com; until it’s up and running, please send an email for purchase options: linda@steiderstudios.com


  26. Linda, this is one of the best tutorials (on anything)that I have seen! Congratulations!


  27. Thank you so much Terrie!


  28. Cecilia Wian Says:

    Hi Linda,

    I’m kind of late to the party but I’m sure glad I found the tutorial. It looks like great fun!

    Well written and intriguing.




  29. Thanks Cecilia!


  30. cindy Says:

    wow linda that is so cool.
    I need to look at my design book and see what I can make with this.


  31. Great, really looking forward to seeing your glass cake tops!


  32. jim simmons Says:

    Great job, Linda. I really likedd your “powderology” class and am looking forward to using your new medium.


  33. Thanks so much Jim, I loved having you & Jayne in class!


  34. Inspirational. Please would you let me know if there is an outlet in South Africa where I could purchase your medium from or do I need to purchase it directly from America. I do have Bullseye frit in stock, I presume that is the glass powder. I run a Proudly South African teaching studio and would enjoy adding another dimension to the class. Visit my website http://www.glassescapes.com. Carol Mullany


  35. Thank you so much Carol! Your work is wonderful. You can purchase from me direct, I’ve shipped worldwide. The powder I use is Bullseye -08 frit.


  36. Linda, Linda, Linda….you are simply the best! Your photos of the tutorial are top-drawer! Explanations make me want to find the stuff that I purchased and get going on it. Oh yes, that glass blower is awesome! Adding details like that makes me think I need to get serious here!

    Thank you for being patient with me. Cfort


  37. Linda Landig Says:

    I didn’t even know there was such a thing as glass clay! How fascinating!


  38. Yes, and it’s very fun to play with!!


  39. Coral Says:

    Who knew years and years ago, Linda from SRC would become such a star in her own hard work way….At that time, you helped to keep our men safe and now you help to make ALL of us smile in seeing your designs of ART……with a Gift only God can give….


  40. Thank you Coral!


  41. emily Says:

    Hi Linda,
    can you tell me if the glass paste can be fired in a ceramic kiln or is a glass kiln needed? My friend bought your medium, we are just starting our experiments with it.
    thanks for any kiln tips you may have 🙂


  42. emily Says:

    Hi Linda,
    I’m just starting to experiment with glass paste, my friend bought your kit for us to try. Do you have any advice on kilns you could offer? We have a basic ceramic kiln, do we need a glass kiln for this technique? Thanks for any advice.


  43. Yes it can. The trick is to go slow to burn out any organic matter, vent so nothing is trapped in your kiln.


  44. Hi Emily, you can use any kiln. You have to know your kiln (what happens at your target temperature) and be able to observe what is happening inside the kiln as you fire.


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