MathType equations are pasted as pictures from the Office Clipboard
TechNote 149
Applicability
The information on this page applies to:  



Terminology
In this article, we will distinguish between the Office Clipboard and the system clipboard by using only those terms. When we refer to the system clipboard, we mean the clipboard maintained by the operating system — Windows or macOS — and generally available to all applications that access the clipboard. When we refer to the Office Clipboard, we mean Microsoft's special application of the system clipboard, available only in Microsoft Office applications. Even though it is only available to paste into Microsoft Office applications, the Office Clipboard can access most objects and data on the system clipboard, and makes it available to paste into Microsoft Office applications like Word, PowerPoint, and Excel from other applications like MathType.
Issue:
When using the Office Clipboard, MathType equations paste as pictures that won't open in MathType.
Reason:
When you copy a MathType equation, MathType puts the equation onto the system clipboard in several formats. MathType works with hundreds of software applications and websites, and not all of these use the same format. Some work best with images, and some with text formats such as MathML. It is up to the target into which you paste the equation to determine which of these formats to paste.
When you copy equations directly from the MathType workspace, the Microsoft Office Clipboard retains the equation in the format of a picture.
Solution:
If you're not familiar with the Office Clipboard, including how to set it up and keep the pane visible while you work, see Microsoft's documentation for Windows or the "Dummies book" documentation for Mac Office 2011. On the Mac it's called "Scrapbook".
If you're using Office 2011 for Macintosh
Our only advice if you're using Office 2011 is to not use the Scrapbook for pasting MathType equations. (In fact, we don't recommend pasting them at all; we recommend you use the toolbar button or menu command for that purpose.) There's nothing you can do about the fact that equations inserted from the Scrapbook are pictures you can't edit. If this doesn't impact your workflow, then there's no problem using the Scrapbook. Just be aware that 1) the equations will not align properly with text when inserted into Word, and 2) your only reasonable option if you need to edit one of them is to delete it and replace it with a new one.
If you're using Office 2007 and later for Windows
There are two situations whereby equations can be placed onto the Office Clipboard, and when you paste these equations into your document, the behavior of one is different from the other. The situations are:
 Copying an equation directly from the MathType workspace
 Copying an equation from Word or another Microsoft Office application
NOTE: Our recommendation is, and has always been, to insert equations into Microsoft Word and PowerPoint by means of the commands MathType provides for this purpose. On the MathType tab in both Word and PowerPoint, there are button(s) that will insert an equation. When you insert equations in this way, it prevents many of the problems mentioned in this article.
If you copy equations directly from MathType, they will be placed onto the Office Clipboard as an image. When you insert these equation pictures into your document, you will not be able to edit them in MathType. Note this is only true if you click the equation's thumbnail on the Office Clipboard task pane. If you paste directly into Word, either with a shortcut key or by clicking the Paste button on the ribbon, it will paste as an "OLE object" that can be edited in MathType. Note also that, as mentioned previously, this is not how we recommend inserting equations (and if you're pasting from MathType 6.9 into PowerPoint 2013 or PowerPoint 2016, it won't paste as a MathType equation at all).
If you copy equations from within Word or another Office app and click their thumbnail in the Office Clipboard task pane to paste into the document, they will be editable in MathType, just like "normal" MathType equations. Doubleclick to edit. Be aware that there are slight differences between applications though. For example, if you copy an equation from Excel and insert it into Word from the Office Clipboard, it will be "floating" (i.e., you will have to move it into position, and it will not look & act like part of your text — unless you change its Layout properties to "inline with text").
We hope this has been helpful. As always, please let us know if you have questions about this, or if you have additional techniques that work. We'd love to hear from you.