How did rave promoters and designers make these?

My theory would be they do a serigraph print of their design and then re-scan it, but I'm not sure at all.

Screentone, stencil, hand-illustration, and heavy application of physical photographic filters. The patterns in the first image, say, were all physically cut from rub-on decal sheets printed with them.

>>317548
for example, likely process:
cut out a photograph of eye
paste it to paper
draw a box around it
apply circular pattern tone over upper-left quadrant
photograph
apply premade tone crosshair to negative
print twice and paste to paper
cut four strips of light tone, apply over photographs
apply tone (or stencil, but you can see a bit of the tone pattern in EMPIRE still) lettering
photograph the whole thing
print from that film

>>317561
and this shit, with the several-hours turnaround at every step and the complete restart if there was dust on the paper while applying the tone (or the ugly-ass blotch like to the right of the H in Portsmouth), explains a lot about why a $4,000 Macintosh and $1,000 for Photoshop or $2,000 for Letraset Color Studio, to work in black and white at fax resolutions, was considered an amazing step forward for design work.