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.

[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