Making a mask for a negative carrier

[thisispants]

Hi, I've only got a 6x9 negative holder, but I'm keen to enlarge some 35mm film. I'm just wondering what material people have found to be most effective at completely blocking light. Is cardboard thick enough? Plastic?
Thanks.

[Valerie]

I've made negative carriers using black mat board.

[Mainecoonmaniac]

See if you could find a plastic 35mm slide mount then use black tape to adhere it to you 6x7 cm carrier.

[Dave Swinnard]

I used to use a glass carrier (had one around) and the black plastic that Ilford papers come in. Before the black plastic bags, I used the black "paper" (sometimes apparently a multi-layered product) that papers came in. In the glass carrier it worked like a charm.

[Bob-D659]

The backing paper for 120 film makes a pretty decent mask as well, free with every roll of film.

[thisispants]

Is cardboard a possible material that would work to make a neg carrier?

Mat board sounds good, however the 6x9 carrier I have has anti newton glass in it, and I was thinking I'd get something quite thin to I could just pop it between the glass in the proper carrier.

I have a feeling mat board is too thick to do this.

[Bob-D659]

Try the 120 film backing paper.

Edit: Ilford backing paper is approx 0.0045" some unknown b&w 35mm film reads approx 0.0054"

You can cut it to mask the image area or include the sprocket holes and the film will still be clamped between the glass plates.

[ChuckP]

I make masks for my glass carriers out of black construction paper. My wife was a teacher so we always had some around. Probably get it at any teacher store.