Development time

CatLABS CatLABS X Film 320 (120/Sheet) in XTOL

11:00 at 20°C, stock dilution, box speed.

Start timer · 11:00

Time

11:00

Standard

Dilution

Stock

Temperature

20°C

Box speed

ISO 320

B&W

All 2 times

Dilution	EI	Time	Temp	Agitation	Timer
Stock	320	11:00	20°C / 68°F	Standard	Start timer
1+1	200−⅔ stop	15:00	20°C / 68°F	Standard	Start timer

EI is the speed the film was rated at when shooting. Times marked “not yet verified” come from secondary sources and haven’t been checked against a manufacturer datasheet.

Other temperatures

18°C	19°C	20°C	21°C	22°C	23°C	24°C
13:45	12:19	11:00	9:54	8:48	7:55	7:09

Calculated from the 20°C time using Ilford’s temperature compensation factors, not taken from a datasheet. Most B&W developers behave well between 18°C and 24°C.

Mixing

Dilution	300 ml (one 35mm roll)	500 ml (one 120 roll)
Stock	Use as mixed, undiluted	Use as mixed, undiluted
1+1	150 ml developer + 150 ml water	250 ml developer + 250 ml water

How they work together

XTOL: Fine grain, high acutance, full film speed, normal contrast. Excellent shadow detail with wide latitude.
CatLABS CatLABS X Film 320 (120/Sheet): Different emulsion from the 35mm version (which is Kodak Double-X). Origin unclear - likely aerographic stock with finer grain.
Notes on this pairing: Highest acutance, moderate contrast.

CatLABS X Film 320 (120/Sheet) in other developers

510-Pyro