Maker: American Colortype Company aka AC CO

You stand HIGH with me

4 1/2" x 4"
dated 1940  
Standing Fold-Out
marked: A.C. Co
for American Colortype
Product of U.S.A.
102
x/.

Just WHISTLE and I will be your Valentine - When the whistle gives its sign I'll be with you dear Valentine.

4 1/4" x 4 1/4"
circa 19300s, 1940s
Single Fold
marked: A.C. Co.
Product of U.S.A.
114

She Loves me, She loves me not

3 3/8" x 4"
circa 1910s, 1920s
made in USA
by American Colortype Co
Flat

American Colortype Co often used the mark AC Co. They were founded in 1904 and active into the 1950s. Among their offerings were stereoview cards, postcards, greeting cards, chromolithographic prints, paper dolls, advertising and more. The company was large and at one point owned the Sam Gabriel Co. Some of their more sought after items were those created for the 1933 Chicago World's Fair.

Dear Valentine ~ You're mine ~ I have captured your heart.

4 1/2" x 2 3/4" (4 1/2" x 5 1/2" opened) 
circa 1930s
   Single Fold
 marked: AC Co
Product of U.S.A.
156