Material for Masking: Contact Printing with UV

[Ken Lee]

Could someone recommend a good material, out of which to cut masks for contact printing via UV light ?

Ideally, the material should be quite thin, so that it allows the glass from the vacuum frame to flatten both the film and the mask.

I would like to make my own masks in a variety of sizes, using a simple cutting tool and a ruler, if possible.

Naturally, the material must be opaque to UV light.

Many thanks !

[brook]

Ruby lith?

[sanking]

Many alternative printers use a sheet of thin mylar between the negative and sensitized material because of the risk of damage to the negative. If you use mylar you can then just tape the negative to the mylar and mask it with rubylith tape of 1/2" to 1" wide.

[Richard Ide]

Hi Ken

There are a couple types of product which you may find of use. For your intended use colour choices are red, amber and medium to dark yellow.

Rubylith/Amberlith are two products which have a coloured lacquer coating on clear film. You cut your design and peel off the areas where you want exposure. This can be used for quite complex patterns. Suppliers would be companies which cater to the printing industry and probably fairly expensive now due to the digital revolution in the print industry. Some art stores also sell it.

Masking film. Available in red and orange, this material is used for splicing in negatives for offset printing. It is a translucent vinyl sheet easily cut with an exacto knife. Try scrounging a few sheets from a neighbourhood printer. A printer would probably have yellow paper masking as well.

Vinyl self adhesive coloured film such as used for signs. A local sign shop would be a good source as would be some art stores as well. They can show you how to transfer the film from the backing onto clear film after you have cut your design.

All the above are transparent or translucent so can be prepared on a light table if desired

Hope this helps and I can give you more information if desired.

Richard

[Ken Lee]

Many thanks !



I'm finally making my first decent Pt/Pd prints, and masking the borders is important. This is a crop from an 8x10 negative.

http://www.kenleegallery.com/images/gallery/HadleyMay2005.jpg

[John Berry ( Roadkill )]

Since it is opaque to UV what about pictorico hi-gloss white film?

[John Berry ( Roadkill )]

Nice shot by the way.

[Ken Lee]

A little clarification would be helpful please.

Is RubyLith composed of 1 or 2 layers ?

Let's say I want to make a mask for a 5x7 images, so I get an 8x10 piece of RubyLith. Using an sharp blade, I cut and remove the opaque material in the center, creating a transparent region that is 4 3/4 x 5 3/4 in size.

Is that transparent area emtpy - or is there still a layer of clear material, from which I have peeled away only the top red layer ?

Sandy: If RubyLith is composed of 2 layers, could I use the RubyLith in place of a layer of Mylar, between the film and the sensitized paper ? If not, then where does the mask go ? Above the film, just beneath the glass ? Where can one get Mylar sheeting in the appropriate size and thickness ?

Thanks in advance.

[sanking]

Ruby lith is not two layers, and you could not use it in place of mylar. Ruby lith is a red material that absorbs virtually all UV light and you use it to mask the edges of the negative. You can do this either by cutting a rectangle in a sheet of ruby lith, or by taping a ruby lith mask on the sheet of mylar. You can buy fairly thin mylar sheets from Light Imprssions in about 3-4 mil thickness. Some flower shops carry sheets of an even thinner mylar.

If you print with the negative in direct contact with the senstized material be absolutely certain that you allow the paper to dry completely before printing. If there is a moist spot on the paper it will stick to the negative and result in a spot on the negative that is impossible to remove.

[Richard Ide]

Ken

As per my earlier post: once you peel off the red coating, you have a clear mylar sheet with what you need blocked out remaining.

Richard

[David F. Stein]

Check with lithographer's supply house. There is a yellow, gridded paper which is ued for what you seek. The name escapes me, but I use it all the time to mask negs. Much thinner than rubylith.

[Brian Ellis]

If all you're interested in is a border mask to eliminate the black border of a contact print you can put black electrical tape around the edges of the contact printing frame glass. That's what I did and it works fine. But this seems so easy, without the need for unusual materials or worrying about precisely cutting out the center of the material, that I figure there must be something more to what you're trying to accomplish than I'm understanding. Several of the people who responded seem to assume you want a mask to use in dodging a contact print and if that's the case then of course you'd need something more elaborate than electrical tape. But then others talk only about border masks so I don't really know what you're trying to accomplish but if it's just a border mask then electrical tape on the glass will work fine.

[Ken Lee]

Brian - I shoot 5x7 and 8x10 and have an 11x14 UV light source+vacuum frame made by Edwards Engineered Products (http://www.eepjon.com/uv.htm" target="_blank).



Most of the time, I want to eliminate the black border on hand-coated Pt/Pd prints, for aesthetics. Some times, I want to crop an image, like when I do a "panorama" with my 8x10 camera, or when the composition is better than originally planned (as in the image above, cropped from an 8x10).



So I need to make a variety of masks. Thanks for the suggestion about electical tape. This can make do in a pinch - and it almost adds another usage to the list for the esteemed "Duck Tape" (http://www.exploremaine.com/~joeho/tape.htm" target="_blank).



Sandy + Richard - It appears that there are two kinds of RubyLith, made by Ulano (http://www.ulano.com" target="_blank) so you are both right. I'll try to get some and see which one works better, etc.



According to the Ulano site,

"Rubylith® and Amberlith® are available in both high and low tack (quick stripping) formulations. High tack film is manufactured with an adhesive which produces a tight bond between the film membrane and the polyester backing sheet. High tack films are suitable for all types of cutting, but are particularly suited to the cutting of fine lines or details. Low tack films are produced with an a dhesive which allows the film membrane to be peeled easily. The "quick stripping" film is best suited for cutting masks or positives which are bold or large format."



"The backing sheet, or support, provides dimensional stability to the film. Although masking film coated on 300- gauge polyester is predominant, 500- gauge polyester is recommended when the application requires tight registration or the mask or positive is large format. Rubylith® is available coated on both 300- and 500- gauge polyester. Amberlith® is available in 300- gauge only."

[Richard Ide]

Hi ken

Here is a suggestion which may provide an easy and perhaps cheaper answer for your needs. From an art store get some clear mylar and a roll of 3M no."616" red lithographers tape. This would give you a long lasting result. There are other brands available which are cheaper but the adhesives break down in a couple of years. If you use rubylith get the high tack and there will be less tendency for the lacquer coating to lift over time from handling.

Richard

[Matt Miller]

Ken,

You can get some rubylith cheap here to try out: http://www.scopestuff.com/ss_redm1.htm

Free shipping too. It works for me.

[Ken Lee]

Thanks Matt - I ordered a few sheets and will give it a try.

I found that my local Art Supply stores do not carry it - so your info was quite helpful.