Why Do These Two Stamps Have Straight Edges?

These two stamps are both perf 11. I believe the Roosevelt is 557 and the Harding 610. The Roosevelt has two straight edges (RB) and the Harding one (T). Is this where a large block of sheet stamps were cut into smaller sheets or did these stamps come in booklet form?

Yes, this is where the press sheets of 400 were cut into panes of 100 for retail sale. Evidence of the natural production process. The blue cutting lines show on the ROosevelt stamp.

Would these be considered more valuable than the ones perforated on all sides?

More information can be found here
https://stampsmarter.org/learning/I...reLines.html

Don

Would these be considered more valuable than the ones perforated on all sides?

Theoretically, yes. For example, the 5 cent Roosevelt has two straight edges, both edges showing the cut lines. Only one stamp in 400 can have that configuration. Even though this type of stamp is in low supply, demand is also low. Undesirable to most collectors who want a fully perforated version.

That probably makes it for an interesting "hunt" to collect all possible variations of edges for a specific stamp, at least from my perspective of a beginner collector, that makes it very interesting

This recent thread may also be helpful....
https://goscf.com/t/86032&whichpage=1

And this thread which has images of a few pages of a guidelines catalog from c1935 when they were more popular to collect....
https://goscf.com/t/47127

"or did these stamps come in booklet form?"

This is not criticism, but to know if relatively common examples of these denominations like yours could not come from booklets because booklets were only issued in certain of the lowest values "is pretty basic stuff"...
a copy of the Scott catalog, even years old, will show what issues have booklets. Barring that, some browsing of major price lists online (e.g. the Brookman sales catalog) will also show. Before the 3c letter rate Thomas Jefferson stamp of 1938 (Scott 807), I don't believe any booklet panes were made besides 1c or 2c values.***
(The 2c Harding was a memorial issue so not surprisingly only came in sheet form. They didn't replace the 2c Washington (Scott 554) with it, so 2c Washington booklets continued to be printed and sold.)

***- speaking of ordinary postage. there was a 10c Lindburgh airmail booklet pane made before 1938! (edited add)