We can estimate the most probable dates for the start of use for each design and most variations, but unfortunately, not all.  The following are a best guess based on a number of sources, but are subject to correction.

We have listed the introduction dates, but hesitate to estimate the stop date for any particular variation because, of course, there would be supplies of badges left with stores & groups that would be used until they ran out.  So one variation might be around for several years after the design officially changed.

In addition, some badges were produced locally by hand when official supplies were too hard to get, or not available.  We have absolutely no way to date these except to say that they fall within a general design type.

Generally for Scouts:

Badge Style

Year Introduced

Metal badges - 1908
Serge cloth badges - 1909
Felt cloth, no wording - 1910
Felt cloth, Boy Scouts - 1927
Ribbon, unbound - 1930
Ribbon, bound - 1935 (* see additional info below)
Printed - 1942, until end of war
Embroidered on Twill, cut edge - 1946
Melton, Boy Scouts - 1949-51
Smooth tan cloth, cut edge, Boy Scouts - 1957 or 58
Smooth tan cloth, rolled edge, Boy Scouts - mid 1960s
Tan cloth, rolled edge, no words - 1968
Grey cloth, rolled edge, no words - 1994

(Used after war as well. Dating of these is possible from the reverse of the badge. Brown was the 1935-42 era, black during late 1940s to early 1950s, and white for the later 1950s, until the tan cut edge badges are introduced.)

The same basic typology works for other sections with minor variations. For example the last Cub proficiency badges, before the new program was introduced in 1965, had a rolled edge; however, the Scout's before 1968 did not.

There are also some odd ball items, such as the early multi-stage badges and the Scout Experimental Scout Program badges which were different and require separate dating.

In most cases it will be reasonably safe to use the end of the introduction of a new variety as the end date for the previous one but recognizing that this is not completely accurate.  The exception would be the metal badges as both metal and cloth were official for a while.