A drawing from my father's diary. He was wounded twice on the mission to St. Nazaire and received the Purple Heart.
Along with the food and medical parcels, the Red Cross also distributed to every American prisoner a blank diary (named "Wartime Log") and a colored pencil set donated by the YMCA. Very few of these diaries survive today, for several reasons. During barracks inspections, German guards would try to find and confiscate any diaries, so the prisoners had to use and hide their diaries carefully. Of the diaries that weren't found and confiscated, many were left behind when the forced evacuation of the camp began in April, 1945 - some prisoners considered the diaries to be unnecessary weight to carry on the journey across Austria.
In addition to writing about their experiences, many prisoners made drawings in their diaries. Some prisoners would offer to draw in other prisoners' diaries in exchange for a few cigarettes or chocolate (the accepted "money" among prisoners).
Rarely, a prisoner would be able to bribe a German guard to get a camera and film. Prisoners were forbidden to have and use cameras, and both prisoners and guards risked stiff punishment if caught.
Few prisoners wanted to talk about their experiences with familiy and friends. My father spoke little about his combat missions or his time in Stalag XVII B. Over the years, several ex-prisoners have written and published their memoirs.