This document contains some of my personal observations and experiences with Northstar Borocolour colored glass. These are strictly my feelings and opinions and do not necessarily reflect the opinions of the manufacturer or anyone else for that matter.

Northstar colors can be roughly divided into two categories: colors that strike and colors that do not strike. They can be further categorized into several color groups: reds, oranges, and yellows; the cobalt family; transparent and multi greens; opacified colors; exotics; and what I call 'pastel' colors. These categories are somewhat arbitrary and but I list them here because it demonstrates how many of the Northstar colors are derivative of each other. I will discuss them within the context of these categories.

Northstar Ruby was the first Northstar color I tried. It is a striking color that turns an intense transparent red when re-heated. This color used to have a lot of seeds and bubbles in it, but has gotten much cleaner in recent years. Just recently, Paul Trautman has sent me samples of a 'new improved' Ruby that is cleaner and less seedy than ever before. Furthermore, this new Ruby does not 'overstrike' (turn opaque brick-red) as easily as the old Ruby did, so you can work it more. Paul says he is changing all the Ruby and Orange colors over to this new technology.

Ruby (NS07) can be heated back to clear and re-struck many times without damaging or devitrifying the glass. For best results, Ruby should be worked in a neutral to slightly oxidizing flame and, if possible, placed in the annealing oven while still clear. This will result in a very transparent red. Ruby goes very well with Cobalt Blue, Black, Turbo Cobalt, White, Green, and Aqua. It makes excellent casing material, but is only fair for frit and trailing. I generally use Dark Ruby (NS08) for those types of applications. Dark Ruby strikes almost black if applied thicker than 1/8" and annealed while still clear. It's intensity makes it great for very thin trailing and fine frit and it makes very nice twisted lip wraps. I also use it for shards because it can be blown very thin and will still strike deep red. I simulate black on larger pieces of glass by casing Dark Ruby over clear with a layer of Cobalt Blue (NS01) over that.

Northstar Orange (NS05) is one of my favorite colors, but it can be aggravating to use because there seems to be a broad variation in intensity from batch to batch. You have to be careful not to use two different rods on the same piece because, as often as not, they will not strike the same, and could ruin the piece. This variation is due primarily to continuing attempts by Northstarş to improve their formulas. Still, the color is one of the best Northstarş makes. The intensity ranges from a pale transparent orange to a deep almost opaque coral color. This color is clearly a mixture of Ruby (NS07) and Yellow (NS09). Orange tends to strike with a slight opalescence that increases the more you work the rod. This opalescence will appear first with the orange highlights taking longer to strike. The opalescence can be eliminated by reheating the color clear and then striking the piece in the oven, which will result in a transparent orange. Like Ruby, it can be heated back to clear and re-struck many times without any ill effects on the glass. Dark Orange (NS06) is a more consistent color. Like Dark Ruby (NS08), it is very good for trailing, shards, frit, and other applications that are very thin. Also like the ruby, the oranges have had a problem with seeds and bubbles in the past, but Paul tells me that the new technology will apply to them as well and should clear the problem up. Both oranges go well with any of the green colors and look wonderful with Black.

Northstar Yellow (NS09) is similar to Orange in its behavior. I do not use much Yellow, but I have heard that very interesting effects can be achieved by layering Yellow over other striking colors like multi-green (NS03). Yellow tends to stay pretty clear, but if it is re-heated in a reducing flame it will take on the swirly opalescence that is characteristic of yellows and oranges. This opalescence can be avoided by heating the color back to clear before placing the piece in the annealing oven. If annealed clear, the result will be very transparent yellow. The extra Light Yellow (NS34) is even lighter than Yellow. It was designed primarily for overlaying other colors. These rods are so light I have gotten them confused with my clear pyrex stock from time to time. Layering Yellow or light Yellow over Ruby will yield very pretty violet and vermillon highlights.

Amber-Purple (NS13) really needs its own classification, but I am putting it with the reds, oranges, and yellows because it is most closely related to Yellow. But Yellow it is not. Amber- Purple is one of the most unique and difficult to learn of the Northstar colors. Like Orange, this color tends to vary from batch to batch, so you don't want to use two different rods on one piece. The rods look deep yellow when you buy them, but when they are re-heated, they take on a beautiful opalescent violet color. This color is more easily viewed in direct light. If back lit, the glass will look more amber in color... thus its unlikely name. I have had difficulty in getting consistent results with Amber-Purple, but I still use it extensively. The Northstar catalogue says to work the color in an oxidizing flame and then reduce to get the purple highlights, but it is not that simple. Amber-Purple is a color that changes its characteristics the longer you work it. If used in a procedure that only involves heating it one time, it is quite easy to strike it purple. But, more often than not, you must repeatedly heat and re-heat the glass and then Amber-Purple seems to get overpowered by the opalescence in the glass. It becomes more and more opaque until it is actually a deep custard color. When it reaches this stage, it is much more difficult to strike it with purple highlights. If you encase Amber-Purple in clear glass, it is impossible to get purple highlights. Instead the glass becomes an opaque custard color, which is not bad actually, so I case it all the time! Amber Purple goes very well with Orange, Black, and Jade Green. It is intense enough to make good frit and trailing, but makes only fair shards. It is excellent for sculpting, especially if you can achieve final shape with only one or two heatings so you can strike it deep purple.

The cobalt family is the largest group of colors. No less than nine Northstarş colors are in this family: Cobalt Blue (NS01), Irrid Blue (NS14), Turquesa (NS15), Black (NS16), Light Cobalt Blue (NS19), Dark Cobalt Blue (NS20), Turbo Cobalt (NS33), Black Hole (NS35), and Intense Blue-Green (NS38).

There are four different intensities of Northstar Cobalt Blue: Regular Cobalt (NS01), Light Cobalt (NS19), Dark Cobalt (NS20), and Turbo-Cobalt (NS33). But they all share the same general characteristics. The cobalt colors tend to be very clean and devoid of any bubbles or seeds or even striations from uneven mixing. The lighter cobalts are extremely clear and retain that clarity even when heated and re-heated extensively. The darker cobalts are somewhat prone to reducing and should therefore be heated in an oxidizing flame. The darker the cobalt, the more pronounced this problem becomes and therefore, the more oxidizing your flame should be. I use Regular Cobalt for casing and combining with other colors. It is lovely for sculpture and any decorations over 1/8" thick. Light Cobalt is also a beautiful color, very transparent, and is great for casing and sculptures, but should be used no less that 1/4" thick. Dark Cobalt is better for thinner decorations like shards and thick trailing, but is still too light for trailing or frit. It makes very good lip wraps. The darkest cobalt, Turbo-Cobalt, is a terrific substitute for black. It will not look blue until it is drawn thinner than 1/32", but has none of the drawbacks of black and black hole like bubbles and a tendency to bloom. Turbo Cobalt must be worked in a highly oxidizing flame however, or it will reduce and show grey streaks that, once they appear, are difficult to heat out.

Three colors of the cobalt family are striking colors. They are Irrid Blue (NS14), Turquesa (NS15), and Intense Blue-Green (NS38). They are all essentially variations of one another with Irrid being the lightest and Blue-Green being the darkest. They are all a combination of Cobalt and Yellow in varying intensities. Like the cobalts, they tend to be very clean colors, without any bubbles or seeds. These colors are wonderful for casing because of the beautiful way they strike. They tend to turn a kind of bluish green with lovely streaks depending on how it is applied. The opalescence makes this glass more opaque than transparent. I use these colors for casing mostly and apply decorations on top of it, but the Blue-Green (NS38) is dark enough to use as frit or trailing.

Black (NS16) and Black Hole (NS35) are difficult colors to use. I almost never use Black because, in my opinion, it is not dark enough to really be called black. It is more of a grey. The rods look pretty black, but in almost any application, it loses its intensity. It is also very prone to reduction and must be worked in an extremely oxidizing flame. It has a tendency to bubble and bloom so you have to kind of stay off of it, which can be tough to do because it is a very viscous glass. The bloom is very nasty and, once there, is all but impossible to remove or heat out. If you heat it with the flame, the bloom will boil almost instantly. Black Hole has all the same problems, but its saving grace is that it is dark enough to be called a true black. It too has a tendency to bubble when worked and will reduce and bloom in anything less than a flame that is ready to blow out. But it can be worth all the trouble. Black Hole makes some of the best frit of any Northstar color. This frit goes extremely well when applied over orange or amber-purple. It does need a color underneath it though. It doesn't look good applied to clear glass.

The only other purely transparent non-striking color besides Cobalt Blue Northstar makes is Transparent Green (NS24). This glass is a pure kelly green that is not heat sensitive at all. It will, however, reduce, creating unsightly brownish streaks, so it needs to be worked in an oxidizing flame. It is also prone to devitrification if over worked so you must avoid extensive heating and re-heating. I use a great deal of this color for sculptural work and casing. It is not intense enough for thin, delicate decorations like trailing and frit. It goes well with Orange and Root Beer.

Multi (NS03) rods look so much like Transparent Green that it is very difficult to tell them apart. But when they are heated, the difference is very apparent. This color strikes, but depending on what kind of flame you use, it strikes in a number of different ways. Unlike most other colors where I want to avoid reducing the glass, I actually want to reduce Multi. The effects can range from a streaky cream color to almost a brick red. Usually, there are all ranges of these colors present together. The effect can be dramatic, but unpredictable. Multi is great mixed with other colors for bizarre effects and can be cased over in clear which tends to magnify the intensity of the colors. Multi makes good trailing material and decent frit when used on clear glass. It goes well with Ruby and Black. Dark Multi (NS04) is just a more intense version of the same thing.

Root Beer (NS37) is a color that Paul made at my urging. Some years ago he sold me some seconds of a 'failed' color, a variation of Multi that he called 'Root Beer' because of the dark caramel color. I liked it so much that I bugged him to make more. Unfortunately, the color was a result of a mistake and could not be easily duplicated. He tried many different formulas, but was never able to duplicate the original Root Beer. But, the color he came up with instead is in some ways better. Root Beer is a greenish rod that clearly contains some of the elements of Ruby and Yellow. If reduced slightly, it strikes a cool reddish-brown with deep striations. I love to case this glass around a clear rod and draw it out into a curved or twisted shape. The colors look like alabaster or marble, only in reds and browns mixed with greens. It is very beautiful! Root Beer also makes excellent frit and trailing and shards. It goes well with Ruby and Jade Green.

There are only two truly opacified Northstar colors. They are White (NS10) and Jade Green (NS11). Neither of these colors strike.

I used to hate Northstar White (NS10). I used the cathode ray-gun mounts manufactured by Corning and sold to lampworkers as square sticks almost exclusively. But recently, I have re- discovered Northstar White and now think it is a decent color. Its only problem, and the reason I used to hate it, is that it is extremely prone to boiling. You just have to be sure not to overheat the stuff. Extreme care must be taken so that the thinnest areas, where boiling is most likely to occur, do not get overheated. But, if you can succeed in completing your task without boiling the glass, NS10 is the purest white borosilicate glass you can buy. It goes with practically every other color and does not reduce or devitrify at all. By exercising care, I have done every thing from casing tubing to intricate sculptures with it. It is not intense enough to use for fine or delicate decorations, but performs adequately in almost any other application.

Jade Green (NS11) is a strange color. On the surface, it appears to be utterly benign. It melts quickly, draws nicely, and matches viscosity with clear stock better than most of the other Northstar colors. But, in the past, it has had a tendency to check. The checking seemed to occur in certain applications more than others, so was a simple matter to avoid those uses of this color. For instance, I never encased Jade Green in clear glass. It would check every time no matter how thoroughly I annealed it. Although it makes fairly good shards, I never used it that way. It didn't seem to like being stuck onto clear glass in such a thin layer. Paul has informed me that there has been a recent change in the COE of Jade Green, and it is now much more compatible than in the past. As of this writing, I have not verified this, though I plan to try some samples in the very near future. Until then, I will just keep using Jade Green for what I have always used it. You can case over clear with it, trail with it, and sculpt with it. It makes fine lip wraps. It goes well with Orange, Black, and Ruby.

There are three Exotic colors: NS27, 28, and 29. All three are color variations of a glass so saturated with metallic colorants that it fumes and plates when heated. It makes for some rather spectacular results however, when used properly. Generally speaking, you should apply it in an oxidizing flame and then reduce it. But, I rarely bother to try to get this glass to do what I want, instead settling for whatever it wants to do. It rarely lets me down. NS27 is a little greener than the others and tends to strike with more metallic features. It also fumes to a greater degree. This glass makes great frit, but is poor for trailing because it tends to be lumpy and viscous and does not draw nicely. NS29 is redder, fumes less, and strikes with less of a metallic effect. Again, it makes great frit but poor trailing. NS28 is somewhere in between. If worked with care, the Exotics can be used for sculpting, which can yield some really weird colors. It is best when not repeatedly reheated. Exotic frit looks great on clear, Aqua, Jade, or any of the cobalt family of colors. One trick is to case over a clear core with Exotic and then traill or draw some transparent color or clear glass over that, then reduce the glass. The clear trailing will 'resist' the reduction creating some very interesting effects.

I have lumped the remaining Northstar colors together into a single general category I call the pastels. They are : Milkyway Blue (NS02), Strawberry (NS12), Aqua (NS17), Moss (NS21), Polaris (NS22), Pink (NS23), Peach (NS25), Lavender (NS31), Violet (NS32), and Creamy White (NS36). Within this category, the colors Creamy White, and Strawberry are similar, with Strawberry essentially being Creamy White with some Ruby thrown in. Pink, Lavender, and Violet are likewise similar, each being a variant of the other. Milkyway Blue, Moss, Polaris, and Aqua make up the rest of the pastel family. All of these colors share the common characteristic of having intentionally introduced micro-bubbles to make them more opaque. All of the colors behave in much the same way. When you are working the piece, the heated micro-bubbles are enlarged, and appear more prominent. The largest ones, however, burst, and leave only the smallest ones. They, in turn, shrink significantly as the piece cools. The result is that the piece does not end up looking all that bubbly. In fact, Aqua (NS17), Milkyway Blue (NS02), Moss (NS21), and Polaris (NS22) take on a kind of 'metal flake' appearance to them when they cool. These colors all make excellent casing material and can be used for sculpting. They make only fair frit and usually are poor for trailing because they don't draw that well. Of these colors, I use Aqua most of all. It goes really well with Turbo-Cobalt or Ruby. Exotic 27 frit looks excellent on Aqua. Aqua twisted with Turbo-Cobalt or Black Hole makes beautiful lipwrap material.

Strawberry (NS12) is the only one of the pastel colors that strikes. It turns dark red, but because of the micro-bubbles, is considered an opaque glass. There used to be a lighter version of Strawberry that I used a lot, but Northstar no longer makes it. The present Strawberry is very dark and, I think, not as 'strawberry' looking as the old stuff was. Strawberry can be used for casing or sculpting. In all honesty, I don't use it much anymore.

Pink (NS23), Lavender (NS31), and Violet (NS32) are all closely related colors. They behave in much the same way. You have to take off your didymium glasses to tell Pink and Lavender apart. With them on, they look exactly the same! These colors also will appear very different when viewed in different kinds of light. Incandescent light, flourescent light, and sunlight will make significant differences in the appearance of these subtle colors. These colors are not very intense and although they are probably best used for highlights or small sculptural elements, I have seen them used successfully when cased over clear tubing or over a layer of White (NS10). Even though they become quite diluted when used this way, they still have surprisingly intense and beautiful effect. They do not strike and are not sensitive to atmosphere.

Creamy White (NS36) is really more of a light gray than a white, but the micro bubbles give this glass a very smooth texture, thus its name. It is excellent as a base for application of other colors and as a transluscent casing color. There does tend to be some variation between batches with the best being the glass with the finest bubbles. If you get a batch with coarse bubbles, it will be next to impossible to work. However, I have not gotten a batch like that in a couple of years.

Peach (NS25) is another color with a creamy texture due to the micro bubbles contained in the batch. This color is the closest Northstar color to flesh, and so is a good one for doing figures and body parts. It is an extremely tolerant glass, and will put up with almost as much abuse as clear pyrex stock. Milon Townsend did warn me that the seconds are vastly inferior to the firsts, and are probably not worth the money you save by buying them.

Northstar is constantly experimenting with ways to improve its formulas and I am called upon from time to time to test new glasses for Paul. Recently, he has sent me some other colors that he has opacified using the micro bubbles. These include Orange and Ruby. The opacified orange is a real breakthrough. It is lovely to work with, creamy in texture and very consistant in its striking characteristics. I hope to see more of that in the near future. Another recent innovation is the introduction of smaller diameter stock in certain colors. These rods average about 4mm, and are perfect for casing color over clear rod and especially tubing. I have used Cobalt, Amber- Purple, and Irrid in the 4mm size with excellent results. I believe it is much quicker and more efficient to case with this size than with 6mm or larger rods.

Northstar has developed several new colors and a couple of them are really fine! Paul sent me samples of N41 (Butterscotch), N42 (Cinnamon), and N43 (Rust).

The Butterscotch is kind of a variation of Amber-purple, only without the purple. It is an opaque striking color that has a creamy-yellow appearance, hence its name. It makes great frit and trailing because of its relative intensity and silver content. It strikes to a deep caramel color with a faint metallic sheen and pinkish highlights. It seems highly sensitive to atmosphere. It is very clean and the samples I have seen do not have any bubbles or seeds in them.

The Cinnamon is only the third transparent non-striking color made by Northstar in addition to cobalt (01) and transparent green (24). It is a dark amber-cola color that is not sensitive to heat or atmosphere. About the only way you can damage it is to overheat it and cause it to boil. The rods are clean and clear and the glass stays that way when worked. It is not very intense so it is not much good for frit or trailing but will work fine for casing and sculpture. It and the butterscotch were made for each other and look wonderful together.

Rust (43) was designed as a substitute for the old Ruby (07) that is now very expensive due to the great increase in price of one of its most important ingredients. This version of Ruby lacks the vibrant intensity of (07) and, although it still does strike, it is nowhere near as red. Striking color is closer to reddish-brown. It isn't very intense, so it is great for sculpting and casing. You don't have to dilute it to work with it. It is actually quite pretty and I expect to be using quite a bit of it.

Those are my notes about the 36 Northstar colored borosilicate glasses. Every lampworker will have different experiences and therefore different opinions about certain colors. Just because I don't like or don't use a particular color does not mean that it is no good. It just means that I don't use it. I encourage you to experiment with color combinations of your own, and to share your results with others so that we can advance our industry together. Whatever you do, TAKE NOTES so you will remember what it was that you did to get that amazing effect!

Northstar Borocolour is in a continual state of development. Color formulas are changed and improved frequently. I like to think that I have had an influence on the developement of some of these colors and Paul encourages other lampworkers to give him feedback on what they like or dislike about the colors they buy from him. You can write to Paul Trautman at 9450 SW Tigard St., Tigard, Oregon 97223, or call or fax him at (503) 684-6986. You can write to me at 265 Rita Blvd., Melbourne Beach, FL, 32951; or email me on Compuserve (71042,751) or on the internet at ram@iu.net or 71042.751@compuserve.com.