Left: Heavy taper Right: Light taper
One of the major design elements of the Gibson SG is the body's beveled edges. Over the years, there has been considerable variation in the style and depth of the beveling. Being done by hand, it can even vary substantially within the same year, but it became noticeably more consistent after the 1960s. With the introduction of the SG-62 in 1986, there was a divergence in beveling style/depth between models based on the SG-62 and the other SG models. Then, with the introduction of the Historic Collection SGs in 2000, another new style was added alongside the other two. More recently, there has been a proliferation in changes to beveling style with new models being introduced and the much more frequent redesigning of existing models since 2014.
Another aspect of beveling style is how, if at all, the horns are tapered. The original Les Paul / SG models featured horn tips that tapered to the depth of the bevels. This is easier shown than explained, so see the picture to the right. As the bevels decreased in depth through the 1960s, tapering naturally waned as well until the bevels no longer even touched each other at the horns. Only with the SG-62's introduction in 1986 did this technique return. This was exclusive to the SG-62 and any models that used the same body (like the Custom and SG-90), while the Standard (and any models using the same body, like the Special) did not have tapered horns even after 1986. In 2000, the SG was redesigned for the Historic Collection with increased tapering to match the deeper, more historically accurate beveling of those models.
Standard vs. '61 Reissue body (1991 - Present)[]
As you can see above, the body design of the Standard has the controls further inboard, whereas the '61 Reissue has them closer to the edge of the body. On the back side, the Standard has a larger, more rounded control plate which is of course set further inboard, while the '61 Reissue has a smaller and more angular control plate. All of this can help in determining which body a given model is based on. Typically, the body design includes the heel shape as well. In terms of beveling, the biggest differences are the treble cutaway bevel and the outer bass horn bevel being deeper on the '61. Another difference is the lack of a treble cutaway bevel on the back side of the '61 Reissue. In 2013, the Standard was redesigned with the body and beveling of the '61 Reissue. The old style would return in 2016 on the Standard T, while the Standard HP would use the '61 Reissue body/beveling. That would continue until 2019, when the Standard and Tribute both gained the '61 style beveling and control placement, while retaining the old style heel design.