Sunday Strip

A special format of Newspaper Comics. Instead of the three to five square panels afforded to the weekday episodes of a newspaper comic, the gaudy Sunday editions of newspapers often feature luxurious color episodes taking up half a page each. These larger comics allow the cartoonist to engage in longer, more elaborate gags than are possible in a typical weekday strip.

Sunday Strips, being quite clearly differentiated from their weekday counterparts, are often used for non-Canon stories, or even separate Story Arcs altogether. This is sometimes done because not all newspapers that carry the weekday strip carry its Sunday counterpart. It is also sometimes done because the artist produces the weekday and Sunday strips on separate schedules (since the Sunday ones need more lead time to set up for printing). More often, though, they simply continue the story being told in the weekday strips, or lack thereof.

Newspaper Sunday strips use a version of Edited for Syndication. The top row of a strip may be discarded by papers that want to fit more strips onto a page, and therefore has to contain a literal throwaway gag which is usually unrelated to the rest of the strip, or at least the rest of the strip still makes sense if it's removed. The panels are also expected to fit into certain formats so they could be rearranged to accommodate different newspapers' layouts and/or take up even less space still. Bill Watterson of Calvin and Hobbes protested against this practice and demanded (and won) the right to produce a Sunday strip with a fixed layout and no throwaway panels, but this was still an exception to the rule; it helped Watterson's case that he was, even by that point, looked upon by many as the benchmark for pushing the bounds of what a newspaper comic strip was capable of.

Sunday strips are published a day early in Canada due to blue laws in the past that prohibited the publication of Sunday newspapers in most provinces, making the Saturday paper the biggest edition of the week. (These laws were mainly repealed after World War II, but most newspapers still publish the comics on Saturdays.) Back when newspaper comics were Serious Business, Americans living in border cities would often travel to Canada on Saturdays for the sole purpose of getting the Sunday strips a day before their neighbours.

Despite not being newspaper comics, several Web Comics participate in this trope. After all, Sunday strips look a lot nicer than normal strips—but they take more time and trouble. Using both allows some beautiful strips while lowering the chance and severity of Schedule Slips; and because it's already done in print media, it's accepted on the 'Net.

Examples of Sunday Strip include:

Newspaper Comics - notable variations

Disney's Sunday strips were an entirely different thing from their Daily Strips. José Carioca and Panchito made their debuts in Sunday Strip form, up to a year before their respective movies debuted in North America.
A few years ago, FoxTrot ended its weekday strips and went to Sunday strips only.
Mark Trail uses its Sunday strips for PBS-style nature lessons. (Though it occasionally goes off-topic a la Network Decay.)
Slylock Fox turns its Sunday strips into entire miniature activity pages, with a Slylock mystery, a six-differences puzzle, a how-to-draw, and a featured drawing, with the throwaway panels being used for a gag involving two kids.
The above case of Calvin and Hobbes, which in addition to being the first strip in decades to be printed in an unbroken format in every paper, also became the reason many papers print some strips down the side of the page, one panel per row: Some papers, not wanting to use up the whole nearly-half-page on Calvin and Hobbes, printed it and a few other strips at a smaller size, with one strip—usually Doonesbury, which is almost always nine identically-sized panels—laid out down the side. This led to...
...Non Sequitur being laid out in two different, seamless, unbreakable formats, the traditional two-row strip and with the panels stacked vertically. This is all done by the artist before submitting the finished product to the syndicate.
Opus was also offered in an unbreakable format, and, unlike Calvin and Hobbes, was initially required to only be printed full-size.
Close to Home used to run two normal-sized strips on Sundays, but now runs one big one.

Web Comics

Narbonic featured a variety of material on Sundays - reader art, reader poems, a Spin-Off arc recasting the characters in a Victorian pulp serial Homage, and a particularly long Fanfic called "A Brief Moment of Culture." (It was about sentient yoghurt.)
Schlock Mercenary
Sinfest
Sluggy Freelance used these for a while. For the past few years, however, Pete Abrams has greatly relaxed the strip's format; nowadays strips can vary from a single black-and-white panel to two pages of full-colored, extra-size panels, and anything inbetween.
Dominic Deegan: Oracle for Hire
- It used to be that these were normal strips, just colored. Nowadays, they've moved into once-a-week, single-panel splash pages, often without dialogue.
Arthur, King of Time and Space has extra-long Sunday strips. Recently these have become story-free "sketch Sundays", often serving as reminders of things that are important to the strip's mythology, but can't easily be worked into dialogue.
No difference in size, but at one point, The Wotch was telling one story on weekdays and a different one on Sundays, the Sunday story being a continuation of its earlier Crossover with Accidental Centaurs.
In late November 2008, Least I Could Do recently added a Sunday update that is large format, a different art style and all flashback.
And Shine Heaven Now usually sticks to three-panel strips from a given storyline during the week, but the Sunday Edition provides a space for Filk Songs, Fourth Wall Mail Slot Q&As, one-shot gags, non-canon parodies, and other material that has nothing to do with the main story.
The Unshelved Book Club has appeared most Sundays since mid-2005.
Squid Row
Precocious
Kevin and Kell not only has bigger Sunday strips, but they used to have a newspaper-style throwaway top strip (the author also draws newspaper comics On the Fastrack and Safe Havens). More recent Sunday strips are much taller, to allow for publication in Bill Holbrook's local newspaper.
Mr. Square Has a Monday strip featured in color in light of this tradition.
Nuparurocks' Comics has done this since its switch to a daily format in late 2008/early 2009.
El Goonish Shive started out like this, and followed the format for exactly 12 weeks. The next week onwards it moved on to a different format, and eventually abandoned the daily schedule as well.