I've tried recently to make 4x5 contact prints from a black-and-white film sheets. Below are my notes on how I approached it.

Chemistry

I used the following chemistry:

Developer: Ilford Multigrade at 1:9 dillution ratio
Stop bath: Ilford Ilfostop at 1:19 dillution ratio
Fixer: Ilford Rapid Fixer at 1:4 dillution ratio

Getting chemistry to the right temperature

I wanted to follow Ilford recommendations of using chemistry at 20 degrees Celcius. As it was my first time developing film and paper at home, I had no useful equipment such as a thermometer. To get around this, I poured a cold tap water into a large bowl and threw my Garmin watch inside. After a few minutes the temperature it reported settled at 24 C, so I threw in a few ice cubes to get it to 20 degrees.

A bowl filled with water. A Garmin sports watch is submerged in it. — The only thermometer I found at home that was capable of measuring down to around 20 degrees Celcius.

Mixing correct amouts of chemistry and water

To fill my tray to around a half height, I needed 300 ml of liquid in each. To achieve the correct dillution ratio, I needed to measure:

30 ml of developer with 270 ml of water (1:9)
15 ml of Ilfostop with 285 ml of water (1:19)
60 ml of fixer with 240 ml of water (1:4)

Unfortunately my measuring cup didn't have any markings below 100 ml. So I put in on a kitchen scale, zeroed it, and poured water until the reading showed 15 ml. I then marked the side of a cup. I poured more water until the scale showed 30 ml and marked the cup again. And so on.

Paper and light source

I chose an RC paper, as it seemed to me easier to handle than an FB paper. I chose Ilford Multrigrade RC Deluxe, glossy. Because I wanted to make contact prints from 4x5 film sheets, it made sense to purchase paper in the 10.5 x 14.8 cm size (slightly larger than film).

Which side is light sensitive?

Might seem an obvious one, but I wanted to be sure. Usually, the emulsion side of paper is packaged facing up in the box. In case of RC paper in particular, the sensitive side is also smoother, more glossy to the touch.

How to expose the paper?

I didn't have any proper light source, no enlarger, etc. So I took a desk lamp and put it against the wall, so that as little light as possible would get out. I did this to make exposure times long.

A red desk lamp standing in front of a washing mashine, with the lamp head pressed against the wall. — A light source.

My reasoning was that my reflex in shutting the light off after the exposure will be a source of error. If exposure time was 0.5 seconds, and my reflex would be up to 0.5 seconds, then the actual exposure time could be off from the indented one by as much as 1 EV. However, if exposure time was 5 seconds, than 0.5 second more or less would have much less of an impact.

Calculating and measuring the exposure time

Before I made my first paper exposure, I wanted to find out what would be the good starting point in terms of the exposure time. I spent a few minutes researching it, and I found several pieces of information.

Firstly, Ilford states that New Multigrade RC Deluxe is approx. 1 stop faster than MGIVRC. On some forums I saw reports that folks consider MGIVRC to be at around ISO 6 to ISO 25. So it seemed to me that a good starting point for MGRC Deluxe would be to consider it at roughly ISO 25.

(Note that photogrpahic paper is not really rated on the same ISO scale as film - so all I was doing here was an attempt to get a rough estimate, a good starting point).

I also found, on another forum, a rule of thumb that:

A good approximation for Zone V film exposure in Lux.seconds is to take the reciprocal of the film ISO speed and multiply by 10. For example a 100 ISO speed film requires 0.1Lux.seconds while a 400 ISO film needs 0.025Lux.seconds of light for a middling exposure.

source

With this in mind, and my Sekonic L-858D in my hand, I measured the light level in my darkroom with a lamp on would be around 0.25 lux. According to the formula above, I'm going to need to expose paper for about 2 seconds.

A blank, white sheet of developed photo paper hanging on clothespin. — Paper exposed according to light meter readings.

Working in the darkroom

Great thing about developing paper is that safe light can be on at all times. According to Ilford:

Amber/Orange or Red safelights may be used with our standard photographic papers as long as they stop light with wavelengths shorter than 580nm.

(source)

I used a lamp that produces a light at 630 nm with no isues.

Results

My first attempt at exposing paper for 2 seconds failed completely. After developing, the sheet of paper was almost completely white. It was clear I was underexposing significantly.

For the second attempt I increased exposure time by 5 EV to 64 seconds. This time the image appeared and was getting darker very quickly. I was aiming at development time of 60 seconds, but I had to pull the paper out and stop it after roughly 40 seconds. Otherwise it'd be way too dark. This time I overexposed.

I exposued for 16 seconds on my first try. The image was visible, but too light. It was underexposed.

So finally, on my fourth attempt at 32 seconds, the photograph came out looking good. My initial estimate of 2 seconds was off by 4 EV.

Several developed photographs hanging on clothespins on a wire. — Several more attempts.

Things to improve

When I put paper on a table top, and a film sheet on top of it, they would not lay entriely flat. Because of this, the resulting photographs weren't sharp around the edges. I tried putting some paper weights at the edges of the paper, but this shows as pure white shapes on the developer paper, so it wasn't ideal. It would be useful to have a clear sheet of glass around the same size as paper to keep things nice and flat.