I’m guessing white carbon paper was used. It’s cool stuff, but where I live it is like 10 times as expensive as regular carbon paper. 10€ for 10 sheets vs 10 € for 100 sheets for regular carbon paper.
Might be a new formulation of ribbon. There’s a guy in the FB groups experimenting with opaque white and metallic gold inks on ribbon. It looked promising a few months ago – maybe now it’s developed further.
I used correcting film (ko-rec-type) to type addresses on black and dark green envelopes last Halloween. They survived USPS’ automated mail processing machines pretty well. I’ve seen ribbon spools with black over white correcting for sale that may work.
Currently in the earholes: 
That white on black typing is really cool! Love to know how that was done.
I’m guessing white carbon paper was used. It’s cool stuff, but where I live it is like 10 times as expensive as regular carbon paper. 10€ for 10 sheets vs 10 € for 100 sheets for regular carbon paper.
Might be a new formulation of ribbon. There’s a guy in the FB groups experimenting with opaque white and metallic gold inks on ribbon. It looked promising a few months ago – maybe now it’s developed further.
I used correcting film (ko-rec-type) to type addresses on black and dark green envelopes last Halloween. They survived USPS’ automated mail processing machines pretty well. I’ve seen ribbon spools with black over white correcting for sale that may work.
It is white carbon/graphite tracing paper that I gave Susan. Can buy it on Amazon quite cheap.
Link to buy white carbon/graphite tracing paper. 50 sheets for $5.
https://www.amazon.com/dp/B09TK3GXFW?psc=1&ref=ppx_yo2ov_dt_b_product_details
Ghost writing is cool!
I wonder how well the white carbon paper would do for corrections?