# Prevent floats on a single page OR change page margins for a single page

I've got a particular problem with a custom chapter style. Essentially my chapter title is on the left page, then there is a picture on top of the right page (waves, see below) and below the picture, the chapter content (bla ble bli blo) starts.

+--------+--------+
|        |~~~~~~~~|
| Ch. 6  |~~~~~~~~|
|        |        |
|        |bla ble |
|        |bli blo |
+--------+--------+


I've got it working using a modification of \chapter{} for the left page, then

\newpage
\ThisULCornerWallPaper{1.0}{waves}
\phantom{placeholder}
\vspace{200pt}


and then the chapter content starts.

The problem is that floats don't know the top right area is taboo for them, so I might get:

+--------+--------+
|        |~[    ]~|
| Ch. 6  |~[Fig1]~|
|        |        |
|        |        |
|        |bla ble |
+--------+--------+


So {figure} first, then placeholder and \vspace, then content.

I've been looking into two solutions without success:

A) Preventing floats on this first page. I don't know how to do this without affecting all of the document (i.e. flafter) or setting the very first float manually to [b]. I haven't found a way to tell floats to just avoid a certain page or a certain area.

B) Setting the top margin for this page only. I've looked into geometry package, namely

\newgeometry{top=300pt}
\restoregeometry


But this doesn't work. First of all, \newgeometry uses \clearpage, but I don't want clearpages, I just want to change one page margin. I've deleted the clearpages and made my own \newcommands, but...

\newsamepagegeometry{top=300pt}
\restoresamepagegeometry


...doesn't work because it both sets and unsets the margins for the current page, instead of setting them for the current page and unsetting them for the next.

So I tried \afterpage{...} but there seems to be a known (or at least observed) issue that prevents

\newsamepagegeometry{top=300pt}
\afterpage{\restoresamepagegeometry}


from working, while manual placement of \restoresamepagegeometry among the next page text works fine. The above code apparently does not execute \restoresamepagegeometry at all, so the geometry remains at top=300pt for the rest of the document.

Any solution or an idea where to look would be most appreciated.

• Hi! First, I'd like to say that this is an extra-ordinary first question, if only every question on the site showed such a quality! Second, notice that you can use backticks ... to format the inline code pieces, as I did in my edit. Happy TeXing! – yo' Dec 16 '13 at 14:41

Your chapter heading can do the same as article.cls \maketitle which is
\global\@topnum\z@   % Prevents figures from going at top of page.

the setting is global but only affects the current page. Depending on the context, you might need to use \makeatletter ... \makeatother.