Hi
As discussed the resist we use as a beginner is largely dependent on what we wish to create, for simple light etching we may use an airbrush mask or Fablon (light vinyl) then move on to sign vinyl for working a little deeper and then as we get more experienced move onto the more proper resist for carving or deep etching for infill. A lot depends on what you can afford to buy, or what you have available, of course, you may start and stick with the proper resist.
I started out with Fablon then acquired 4 full rolls of sign vinyl maybe 60m long each roll and I have only 2 rolls left; either lots of mistakes or very prolific, so maybe before you make each stencil try out your pattern with a paper print as you can't afford to make mistakes. I say this so that you may get used to checking before cutting as photoresist is very very expensive.
Once you get a bit more advanced into your etching hobby and designs get progressively more complex then you may wish to move onto Photoresist. These resists can recreate to perfection any design you can wish for whether it is intricate line work or photographic images, photoresist can reproduce it whether good or bad it is all down to the design; good in good out, bad in bad out. Not only will it take line designs and photographic images but there is no necessity for the images to be of a vector design as any black printed images whether .btm .jpg .png. or .tif basically anything you see in black and can be printed can be used but the better the quality of the artwork the better the output.
I have just received 5 A4 pieces of 2mil Rapidmask at a cost of £28 or $43 inc postage so not to be wasted on mistakes, also be aware of the shelf life of resist which is around 14 months, when I was sorting out what gear I had left to start etching again I found 4 sheets of Rapid and 2 of washouts which I had to throw away as they were well over 4 years old.
What is photoresist
Photoresist is a light sensitive material that when exposed to UV (Ultraviolet) light changes its form, it can change in 2 ways depending on type.
Washout
Washout resist is the more common of the resist family and is classed as a positive resist.
Wikipedia
This is perfectly explained in this video by John Morris of Cornerstone Glassworks.
So, positive resist means that the design is etched as you would see it on your screen black lines etched while clear areas remain untouched.
Here is an example of what could be a downloaded flourish design in .jpg format.
In this video, we can see how converting a photographic image into a halftone using Photoshop and exposing onto our resist allows us to render the image onto the glass. It is also one of the best photoshop halftone conversion videos I have found.
Have a look at this work using washout resist Lapida online
This type of resist is produced by a company called Rayzist in California and produces 2 different types of resist the first being
SR2000 which comes in 5 different thicknesses from 3mil to 9mil. If using this resist then you also need to buy the adhesive to stick the resist onto the glass, this is probably not the best option for a beginner.
Etching paver using SR2000
SR3000 is Rayzists best resist for glass as it is self-adhesive and comes in 3 different thickness 3, 4 & 5mil, this is what is used in the above videos.
3mil being for detailed artwork and halftones
4mil being for moderate detailed artwork and moderate depth etch.
5mil being for bold artwork and moderate to deep stage carving
It can be used on all types of etching from wood, stone, granite, marble, soft metal and glass of course
The next type of resist is called RapidMask
Rapidmask
This type of resist is classed as a negative resist, meaning the black area's of the design are unaffected by the UV and the clear area's are exposed.
Unlike the washout resist Rapidmask is permanently in a resist state and when exposed to UV light for the prescribed amount of time will turn the exposed resist brittle which will be indicated by a colour change showing the outline of the design. When these brittle areas are hit by our sandblasting they break apart allowing the media to etch our design. There is no need to washout this resist you just expose with the UV, stick on the glass and blast.
PDF INSTRUCTIONS
When after first buying your Rapidmask you need to check the exposure time required to turn it brittle, this may not be a fixed time as each different UV exposure unit may have a different wattage of tube, or tubes. I have not tested my new unit, but this has 6 8 watt black UV tubes so may have a shorter exposure time than a 1 or 2 tube unit.
This guide was snipped from the Ikonics site giving exposure times for different units.
I have been to the Crystal Galleries works and had a tour and instruction from Kevin the General manager and from his instruction these times may well be over exposed, we tried 30 seconds and it worked fine.
Brittle test and using Rapid mask
Ikonics video showing how to use Rapidmask
Ikonics imaging. Showing negative images and using Rapidmask
Very good video on using Rapidmask
Rapidmask comes in two different thicknesses for different applications.
2mil for high detail and halftones.
4mil for halftones and deeper etching / sand carving.
Both types of resist can also be used for stage carving where each section of the pattern is removed in sequence for multi-stage carving.
I have, since originally writing this had a lot more experience of Rapidmask with a lot of success but also a lot of failure and a lot of expensive lessons learnt. Firstly this material does not like convex curves, not really the materials fault more than the plastic cover sheet which is so thick and unweildy that it does not conform to the curve. Next is its hate of the minorist air bubble, when placing the resist a great deal of care and pressure combined to exclude all air bubbles from the underside, also cleanliness hold a big part in the application. All air bubbles must be removed either by roller or pricking and excluding the air, remember these holes must be covered before etching.
UV Exposure Units
I have now owned 3 exposure units although I can't remember using them very much as I tended towards machine cutting as most of the work I made seemed to be always on the large side.
The first machine I owned was a huge great box that weighed around 15kg, it consisted of a 4 tube UV light and had a vacuum pump integrated in the box. A vacuum exposure unit is arguably the best available as the vacuum pulls the resist and the acetate sheet tightly together for perfect exposure. Unfortunately it was designed to sit in a fixed position and never be moved, a luxury I never had, far to heavy and it ended up in the loft and then a skip.
My second was a Letralite exposure unit.
I started out with Fablon then acquired 4 full rolls of sign vinyl maybe 60m long each roll and I have only 2 rolls left; either lots of mistakes or very prolific, so maybe before you make each stencil try out your pattern with a paper print as you can't afford to make mistakes. I say this so that you may get used to checking before cutting as photoresist is very very expensive.
Once you get a bit more advanced into your etching hobby and designs get progressively more complex then you may wish to move onto Photoresist. These resists can recreate to perfection any design you can wish for whether it is intricate line work or photographic images, photoresist can reproduce it whether good or bad it is all down to the design; good in good out, bad in bad out. Not only will it take line designs and photographic images but there is no necessity for the images to be of a vector design as any black printed images whether .btm .jpg .png. or .tif basically anything you see in black and can be printed can be used but the better the quality of the artwork the better the output.
I have just received 5 A4 pieces of 2mil Rapidmask at a cost of £28 or $43 inc postage so not to be wasted on mistakes, also be aware of the shelf life of resist which is around 14 months, when I was sorting out what gear I had left to start etching again I found 4 sheets of Rapid and 2 of washouts which I had to throw away as they were well over 4 years old.
What is photoresist
Photoresist is a light sensitive material that when exposed to UV (Ultraviolet) light changes its form, it can change in 2 ways depending on type.
Washout
Washout resist is the more common of the resist family and is classed as a positive resist.
Wikipedia
- A positive resist is a type of photoresist in which the portion of the photoresist that is exposed to light becomes soluble to the photoresist developer. The portion of the photoresist that is unexposed remains insoluble to the photoresist developer.
- The developer in this case is water although some use a chemical.
This is perfectly explained in this video by John Morris of Cornerstone Glassworks.
So, positive resist means that the design is etched as you would see it on your screen black lines etched while clear areas remain untouched.
Here is an example of what could be a downloaded flourish design in .jpg format.
In this video, we can see how converting a photographic image into a halftone using Photoshop and exposing onto our resist allows us to render the image onto the glass. It is also one of the best photoshop halftone conversion videos I have found.
Have a look at this work using washout resist Lapida online
This type of resist is produced by a company called Rayzist in California and produces 2 different types of resist the first being
SR2000 which comes in 5 different thicknesses from 3mil to 9mil. If using this resist then you also need to buy the adhesive to stick the resist onto the glass, this is probably not the best option for a beginner.
Etching paver using SR2000
SR3000 is Rayzists best resist for glass as it is self-adhesive and comes in 3 different thickness 3, 4 & 5mil, this is what is used in the above videos.
3mil being for detailed artwork and halftones
4mil being for moderate detailed artwork and moderate depth etch.
5mil being for bold artwork and moderate to deep stage carving
It can be used on all types of etching from wood, stone, granite, marble, soft metal and glass of course
The next type of resist is called RapidMask
Rapidmask
This type of resist is classed as a negative resist, meaning the black area's of the design are unaffected by the UV and the clear area's are exposed.
Unlike the washout resist Rapidmask is permanently in a resist state and when exposed to UV light for the prescribed amount of time will turn the exposed resist brittle which will be indicated by a colour change showing the outline of the design. When these brittle areas are hit by our sandblasting they break apart allowing the media to etch our design. There is no need to washout this resist you just expose with the UV, stick on the glass and blast.
PDF INSTRUCTIONS
When after first buying your Rapidmask you need to check the exposure time required to turn it brittle, this may not be a fixed time as each different UV exposure unit may have a different wattage of tube, or tubes. I have not tested my new unit, but this has 6 8 watt black UV tubes so may have a shorter exposure time than a 1 or 2 tube unit.
This guide was snipped from the Ikonics site giving exposure times for different units.
I have been to the Crystal Galleries works and had a tour and instruction from Kevin the General manager and from his instruction these times may well be over exposed, we tried 30 seconds and it worked fine.
Brittle test and using Rapid mask
Ikonics video showing how to use Rapidmask
Ikonics imaging. Showing negative images and using Rapidmask
Very good video on using Rapidmask
Rapidmask comes in two different thicknesses for different applications.
2mil for high detail and halftones.
4mil for halftones and deeper etching / sand carving.
Both types of resist can also be used for stage carving where each section of the pattern is removed in sequence for multi-stage carving.
In conclusion
It would be best to try both types of resist to see what is best for you as both appear to be very good although the water wash needs a bit more equipment in the washing equipment but may be a little less confusing with the positive imaging.I have, since originally writing this had a lot more experience of Rapidmask with a lot of success but also a lot of failure and a lot of expensive lessons learnt. Firstly this material does not like convex curves, not really the materials fault more than the plastic cover sheet which is so thick and unweildy that it does not conform to the curve. Next is its hate of the minorist air bubble, when placing the resist a great deal of care and pressure combined to exclude all air bubbles from the underside, also cleanliness hold a big part in the application. All air bubbles must be removed either by roller or pricking and excluding the air, remember these holes must be covered before etching.
UV Exposure Units
I have now owned 3 exposure units although I can't remember using them very much as I tended towards machine cutting as most of the work I made seemed to be always on the large side.
The first machine I owned was a huge great box that weighed around 15kg, it consisted of a 4 tube UV light and had a vacuum pump integrated in the box. A vacuum exposure unit is arguably the best available as the vacuum pulls the resist and the acetate sheet tightly together for perfect exposure. Unfortunately it was designed to sit in a fixed position and never be moved, a luxury I never had, far to heavy and it ended up in the loft and then a skip.
My second was a Letralite exposure unit.
Letralite PDF Instructions
These units are produced by Ikonics and if you are lucky you may find one on eBay which, again foolishly, is where mine ended up. These units have a single large tube and are very widely used. Unfortunately they have a rather hefty price tag for what they are; $330 from Rayzist and by the time they reach these shores they have increased in price to around £338 plus vat = £406 plus £10 delivery. Have you worked it out yet in the States, that's $644 nearly double. Wow
I took a cheaper route, the resist doesn't mind how fancy the exposure unit is.
These units are produced by Ikonics and if you are lucky you may find one on eBay which, again foolishly, is where mine ended up. These units have a single large tube and are very widely used. Unfortunately they have a rather hefty price tag for what they are; $330 from Rayzist and by the time they reach these shores they have increased in price to around £338 plus vat = £406 plus £10 delivery. Have you worked it out yet in the States, that's $644 nearly double. Wow
I took a cheaper route, the resist doesn't mind how fancy the exposure unit is.
I must have hit it right as this unit I bought was on special at £150 and came with black UV tubes and one spare tube.
There are lots of different units out there and of course you could always make your own, just check out YouTube or Instructables as there's a huge amount to choose from.
Paul
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