My recollection of Linen is as a metal work apprentice in the Midland Junction workshops for the railways,1950.
The linen was rolled out on to the board and securely held down. I would have thought glossy side up but memory fades. The sheet was "sized" with a "pomme" filled with very fine chalk.
Apprentices always were very vigorous applying the chalk to ensure that the linen and nearby draftsmen received a liberal coating.
At a later date the compliment was returned with the fake ink blot and upturned indian ink bottle. All to the amusement of the office staff and chagrin of the recipient.
The drawing boards were of a large size set on a bench at above waist height. This meant standing to use them or perching on a bar stool to sit.
At the end of the day boards were covered with a cloth, not sure why.
Drawing instruments were German "Staedtler", I still have mine,,,,,,,,,,,,somewhere.
Drawing mistakes were made and these were removed with judicial use of a very sharp razor blade or scalpel.
later in industry drawing film replaced linen and pencil replaced ink. Time dictated drawing accuracy and freehand replaced compasses.
Enter CAD and that's progress.