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How to make Bullseye fusible glass powders work for you

Bullseye (BE) powders are nothing more than fusible sheet glass ground into fine powder. I've done a lot of experimentation with them, and I want to share what I've learned with you in the form of some Do’s and Don’ts.

I'll start first with the Don’ts so that you can learn from my mistakes and wasted efforts.

Don’t expect Bullseye powders to act like enamels when fused. You can't just sift a light layer on and expect rich color to result; in fact, full-fusing a very thin layer of most BE powders just makes them disappear. This applies to even many of the “opaque” opals. However, you can get interesting composite color effects by adding additional layers of powders over the course of multiple firings.

Don’t hesitate to sift, pinch, or shake on a generous amount of powders. Bullseye techs say that if you want your BE powder to look like sheet glass of the same color, you have to pile on a layer thicker than sheet glass in order to make up for the air spaces in between the particles of powder. So, to get the same color richness of a 3mm sheet of BE glass, you have to pile up 4mm of powder. Remember that you can add additional interest and texture by moving the powders around with brushes or silicone Colour Shapers.

Don't assume that a channel of glass powder (or even frit) is strong enough on its own to hold together two adjacent pieces of glass. Yes, powder can help fill gaps where two pieces don’t fit exactly flush together, but if you want to make a piece that will last, add a second solid layer above or below. And remember that your strength always lies with precision cutting and fitting; don’t expect powders or frit to “bridge” nearby components and “glue” them together without a solid base or cover layer.

Don’t expect clear glass powder to stay clear. Unlike other BE glass powders where piling on a thicker layer results in a richer color, piling up clear powder results in a milky whitish layer. Why is this? Bullseye techs explain that air bubbles get caught in between the particles of clear glass powder, and result in so the thicker the layer, the milkier it becomes.
apply clear powder thinly to avoid a milky effect

To avoid this, just make sure your application layer of clear powder is very thin.

Now that you’ve heard the don’ts, you’re free to explore all the neat things that you CAN accomplish using Bullseye powders:

Do try Bullseye’s “strongest” powders for image and pattern creation--the black opals and the aventurines.

In my opinion, the most versatile BE powder is black opal (BE-00100). It can be applied thick or thin and will retain its distinctiveness and granularity on contrasting color sheet glass. It also will hold a pattern and texture when manipulated with brushes, palette knives, or the silicone Colour Shapers found on our Glass Art Tools website.

Do sift a thin layer of black opal powder over any black sheet glass in your piece: After a full fuse, the glass will be a glossy patent-leather black that covers any imperfections in the glass sheet. Just be sure to use a brush or our mini vacuum cleaner to remove any stray particles from edges or anywhere else they don't belong, or they’ll show up after fusing.

Do consider experimenting with Stiff Black Opal (BE-000101) accessory glasses—both powders and stringer. Stiff Black gets is name because it is more resistant to the heat of the kiln than regular black opal. This is great for stringers: Bullseye’s .5mm Stiff Black Opal stringers retain their straightness and won't wiggle around in a full use the way that regular black opal stringers can.
stringers of stiff black opal keep their shape

Stiff Black Opal powder might be the way to go if you really want to retain the definition of every grain, although it will blend perfectly into black background glass during a full fuse. However, be prepared: Stiff Black Opal on the surface of your plate or bowl might make it take surprisingly longer to slump. Being “stiff,” it resists bending! So watch your glass carefully and expect to take it at least 10 degrees hotter and perhaps hold it longer than usual in order to get your perfect slump.

Do try Bullseye Aventurine Blue (BE-001140) and Light Aventurine Green (BE-001412), Bullseye powders that combine color, sparkle, and more definition than regular transparent powders. I especially like Light Aventurine Green powder because it can be applied more thinly and manipulated like black, but it shows up better against darker background glasses.
Light Aventurine Green powder test samples

Do choose Opaque White (BE-000013) instead of regular White Opal (BE-000113) because, according to my tests, Opaque White seems to hold its definition better under higher temperatures. It shows up best when tack-fused as opposed to full-fused.

Do try playing with a combination of coarse frit and powder: I’ve found, at least with transparent colors, that when they are contained together in one area, they create a mosaic effect after fusing.


Do
consider texture-fusing powders. Here's a photo of a part-sheet that I made using powders and clear stringers:

When fired to a lower range, 1250-1320 degrees, powders retain their graininess and can be “piled” and manipulated to create a “bas relief” surface. And as long as you keep the temperatures within this range, you can re-fire your piece after you've painted on additional colors, such as Reusche pigments mixed with Propylene Glycol. Chalks won't stick at this temperature range, though.

Do tack-fuse a thinly-sifted layer of powder onto glass to provide a rough layer for applying chalks and paints.

Do help prevent air bubble formation by sifting a thin layer of powder in between layers of glass.

So those are the basic Do’s and Don’ts that I’ve learned in working with Bullseye powders. My bottom line rules are:

  • opals tend to show up better than transparents
  • dark colors will show up better against light backgrounds than light colors against dark  
  • the thicker the powder layer, the more visible it will be
  • additional layers (and multiple firings) will add depth and richness of color
  • always experiment on a smaller piece first!

While our Glass Art Tools website doesn't sell glass powders, you can easily obtain them from your local glass dealer or directly from bullseyeglass.com.  Note that they come in a variety of sizes--I recommend starting with the smallest bottle and experimenting with it before you commit to purchasing a pound or more.

If you have any findings that I’ve missed that you think will be helpful to people, or if you have different experiences with a different brand of glass powder, by all means, please share!

Comments on this post (1)

  • Oct 25, 2019

    Very helpful blog, Judy. Please write more!

    — Sharron Barrett

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