You don't really need to practice -it takes a while to file and the change is slow and small. I start one side, file at an angle and then the other side to take a couple millimeters off at a time and use an old/destroyed negative to measure how much is enough for me. Then I file both together so that they're flush. Make sure you wash your carrier, wipe it down well and use some emery cloth to take out the burrs and sharp edges that can scratch your negative. Some tape on each side of the holes to keep the negative off the edges would help too and help clamp your negative a little better.
I have a filed out 35mm carrier, dimensions are 39x28mm, it's bright aluminum and gives reflections. It does show sprocket holes, and longish exposures are needed to have them show as solid black, otherwise they show as holes. I rarely use it. When I do use it, I cut down 11x14 paper to print full frame with black border.
ooops...meant to send a PM...
I'd recommend a glass carrier for 6x6 :).
maybe these two images will help.
i find the effect is MUCH more pronounced when using diffusion heads, or cold light heads.... condensor heads produces an effect that is much less pronounced
mine are filed so i can see clear base film all around the neg.. probably a good 1mm all around..
..the image here was made on a cold light head.
the way ive achieved the 2 solid lines was to make the bottom holder slightly larger than the top.. this matters a lot, because, from what i can tell.. you want the bare shiny metal showing after you file away at the carrier as the more light reflecting off the edge the more youll be able to see it..
i use a variety of bastard files/hand files to achieve this, it takes A LOT of work, at least in my estimation... its hard to file away at these things...
do a buncha test prints along the way to find out what you like, file more as needed...
This is what I do except I use a glass carrier for 4x5.
Originally Posted by MattKing
I spent some time one weekend making a bunch of masks for 35mm and 120 out of black construction paper that let the rebate area show. It started out as making a mask for 127 film, but I just kept on going once I had the paper and Exacto knife out.
Like Rick I found that I don't really like it that much now that I've tried it. But if it words for the subject, then go for it.
File at an angle of 10 deg. Borders will not go black because the blacks in your print are not max paper black.
They simply look that way.
Glass is better. I filed out the top to take AN glass from a glass slide mount. You can not cut it as it is too fragile.
This is a long slow file operation with lots of trial fits to keep square and not go over. Do it well and it will become your favorite carrier.
Omega 4x5 glass carriers have two locating pins where strip film would properly extend. The work arounds are masks cut at an angle or have a shop relocate the pins.
Neither is a nice solution. On older Omegas, the carrier will not rotate to compensate for the crooked neg.