The 1991 Leaf baseball card set was released during the middle of the 1991 MLB season and marked an important year for the Leaf brand. After establishing themselves as a reputable brand in the late 1980s and early 90s, the 1991 Leaf set showcased the company taking steps to compete with industry giants like Topps and Donruss.

Containing 329 cards in the base set, the 1991 Leaf offering featured a mix of current stars, future Hall of Famers, and rookie cards that have become valued by collectors in the decades since. While not quite reaching the production or distribution levels of the ‘big two’ at the time, the quality and design of the ‘91 Leaf set set helped the brand gain more exposure and traction within the booming baseball card market of that era.

Some of the notable rookie cards featured in the set included Chuck Knoblauch (Card #47), Javy López (Card #80), and Jim Abbott (Card #117). All three players went on to enjoy solid big league careers and their rookie cards from Leaf in 1991 are still sought after by collectors today. Another impact rookie was Jermaine Dye, who had one of the more visually striking and memorable designs on his card (#263).

Future Hall of Famers with base cards in the set included Nolan Ryan (Card #14), Eddie Murray (Card #25), Rickey Henderson (Card #29), and Gary Carter (Card #163). Each of their cards highlight stellar careers that had produced impressive stats by 1991. Stars of the day like Dave Winfield (Card #5), Wade Boggs (Card #8), and Mark McGwire (Card #107) also had prominent placements early in the numerical checklist.

Design-wise, the 1991 Leaf offering utilized a clean and uniform look across the base cards. A solid color background was paired with a white or gray border surrounding each player photo. Statistics and a brief career recap were included on the reverse. The fronts exhibited mostly headshots but some action photos were also used. Serial numbers ran along the bottom right corners and the Leaf logo was prominently displayed at the top.

While most collectors at the time were primarily focused on pulling packs of Topps or Donruss, the 1991 Leaf set did introduce several innovations that helped its brand stand out. Perhaps most notably, Leaf was the first mainstream card company to feature traded players in their new uniforms rather than where they started the season. This added an element of accuracy that collectors appreciated.

Another Leaf innovation in 1991 was the inclusion of ‘Traded’ supplemental cards to depict players that switched teams after the initial base set had been finalized. Stars like José Canseco (Oakland to Texas, Card #T14), Joe Carter (San Diego to Toronto, Card #T51), and Vince Coleman (St. Louis to Kansas City, Card #T141) were among those receiving ‘Traded’ updates in the set.

In addition to the base 329-card issue, Leaf also offered inserts like ‘Turn Back The Clock’ retrospective cards and ‘Top Prospects’ minor leaguers to watch. Serial-numbered parallels like ‘Gold’ (/1991) provided coveted short-print chase cards. And multi-player ‘Team Checklists’ recapped each MLB franchise’s roster from that season.

Overall collector and retail reception to the 1991 Leaf baseball issue was quite positive given the rapid growth of the hobby during that era. While still considered the “third major” brand behind Topps and Donruss, Leaf established itself as a credible and popular alternative offering quality content. Prices for most base cards from the set have held steady value-wise since initial release as well.

Key rookie cards like Knoblauch, López, Abbott, and Dye have appreciating in secondary market demand and dollar amounts over the decades. Hall of Famer rookies or early career cards continue attracting vintage collectors. And inserts like the ‘Traded’ supplemental pieces add to the comprehensive nature of chronicling the 1991 baseball season through cardboard.

By implementing small innovations, showcasing all 30 MLB clubs, and advancing the photography/design aspects from prior years – the 1991 Leaf baseball release built momentum for the brand and collector enjoyment. It remains one of the most complete and historically relevant baseball card sets from the early 90s hobby boom era. Three decades later, this issue endures as both an important sports memorabilia and prominent vintage collecting landmark from that time period.

In the end, while not achieving the scale and circulation of Topps or Donruss – the 1991 Leaf baseball card set stands out for the quality of its content, innovative features, and documenting a specific year of MLB that holds nostalgia for many collectors and fans. Key rookie cards, inserts, parallels and capturing the 1991 season continue drawing interest from the hobby. It serves as a snapshot of the sport from that period alongside memorable designs that transported enthusiasts back to summertime games.