Spring is the busiest season for fund-raising events, buoyed by good-and-getting-better weather, the fun of lighter and brighter garb, and the longer daylight hours.

There’s no better indicator of the impending gala-whirl than the bulk of invitations filling up mailboxes in the last week or two, perfectly timed, it seems, to be opened by New Yorkers returning from vacation and, as the nonprofits hope, craving company.

Sifting through invitations is both an art and a science. Some are just too pretty or eye-catching to ignore; they don’t look like invitations as much as miniature magazine covers, artworks, or advertisements. Others rely on more conventional techniques to get the information across, plain and simple. One pet peeve I have is that invitation designs often bury the date of the event, giving prominence instead to its venue or honorees.

Event designer David Monn has a pet peeve too: misunderstandings about the definition of attire as given on invitations. He’s already received questions about the “formal attire” specified for the grand opening dinner at the Plaza Hotel on May 10. He writes about the topic on his Web site, www.davidmonn.com.

Having overseen hundreds of events for nonprofits including the New York Public Library, the Metropolitan Opera, and the Costume Institute, Mr. Monn has strong ideas about what invitations must accomplish.

“It should tell you everything you need to know: what that occasion is going to be about, what am I to do, and what am I to expect,” Mr. Monn said yesterday. Successful fundraising invitations convey the organization’s brand and its mission, preferably with a sense of drama.

When Mr. Monn works on nonprofit gala invitations, he aims for continuity. “When I see something that’s familiar to me, and I like it, I’m going to look at it,” Mr. Monn said. Change, on the other hand, requires more work on the part of the recipient. “When an institution changes its invitation and image every single time, you have to go through the whole thing and be wowed by it every time.”

One must-have invitation accessory is the personal note. Two invitations I received recently came with what looked like handwritten notes from the founders of the organizations. Borrowing a direct mail technique, these notes were actually preprinted, but they did the trick, creating a semi-intimate moment. People serving on event committees often add their own handwritten notes, to alert their friends why they have received an invitation.

No note or design can prevent the predicament many will encounter, of two, three, or even four events on the same night. Negotiating that situation is just one of the costs of being a popular and desired guest. If you wind up in that situation, it’s likely you have the skills to get through it gracefully.

agordon@nysun.com