What are slipcasting molds, and what is the purpose of each mold?

Sure, lets break it down. We'll talk about 3 different mold types in this answer, Master molds, Rubber molds, and Production molds. The master mold is a plaster mold that is made from capturing the contours of a model so a-like product can be cast from it's negative space. Although you can cast from the master mold, we ideally want to preserve this mold so you can replace molds as they wear out. That's where the Mother mold comes in, or the rubber mold. The master mold is sealed to fabricate the rubber mold, and the rubber mold captures the positive area of the master mold, or the details of each master mold part. The rubber mold expedites the mold making process through enabling you to produce working molds at a lower cost and scale production at a faster pace. The plaster molds formed from the rubber mold are called working molds, or production molds. They are identical to the master mold and are the molds used to slipcast your form.

How long do slipcasting production molds last?

The life of a production mold is dependent on the level of detail present in the mold. We estimate 50-80 casts per mold before it needs to be replaced, but again this estimate is dependent on the type and level of detail in the mold. For example, if you were casting a jar with lettering embossed in the mold you would need to replace this mold more frequently than a mold of a jar with no lettering because the smaller details will soften with each cast. Sharp edges and corners are also prone to chipping which could be a factor that requires your molds to be replaced more frequently.

How long does mold work take?

The timeline for mold work is dependent on what mold types you are looking for. Once the model is received we estimate a time period of a week per mold type. For example, we can complete a master mold in one week, a master and rubber mold in two weeks, and a master, rubber, and production molds in 3-4 weeks.

How do I submit my request for a custom mold order?

Please submit a Custom Mold Inquiry by following the link. If you're curious about how we tackle your custom mold work you can take a look at our Process Reference Guide. It's a great way to get acquainted with our process and studio practice.

How do RAM molds differ from slipcasting molds?

RAM molds, or hydraulic press molds, first and foremost do not use slip to reproduce a design. Instead RAM molds press firm clay between a top and bottom mold part to produce a finished item. There is still a master, rubber, and working mold involved, but only one working mold is made to press your piece. RAM molds are more costly than slipcasting molds as they are more work intensive, require more material, and have a longer working life than their distant cousins.

We utilize a 30 ton and 60 ton press in our production facility.

How long do RAM press molds last?

Due to the difference in material and application RAM molds are much hardier that ceramic plaster molds. A RAM mold can typically press 500 units before it needs to be replaced, but like slipcasting molds, the life of these molds are dependent on the level of detail present in the mold.

What glass molds do you offer?

We offer frit and slump mold production. Glass molds are made from an earthenware clay that can withstand temperatures up to 1800 degrees Fahrenheit. We do not offer glass production or materials at this time.

What is your process for a glass mold design?

Your confirmed design will be upscaled to account for the shrinkage that will occur in the bisque process. Depending on the total number of molds you require we will complete a master mold or all three mold stages; master, rubber, and production. When your mold work is complete production of your glass mold begins!

I am interested custom mold work but I have never slipcast/worked with a RAM press before. Do you provide guidance or support?

Although we do not have the bandwidth to assist with general mold and production questions at this time, but we've put together a Troubleshooting Guide to help point you in the direction. We've also noted a few of our favorite mold resources below. If you believe your Mudshark molds are malfunctioning due to a manufacturing defect please contact us directly.

- The Essential Guide to Mold Making & Slipcasting
- Plaster Mixing Procedures

What is slipcasting?

Slipcasting is the process of pouring liquid clay, known as slip, into a plaster mold to produce a clay object, or a casting. The plaster absorbs moisture from the casting slip which creates a layer of firmed clay around the interior of the mold. This layer is then released from the mold as a 3D object that reflects the interior details of the mold.

Slipcasting is used as a production technique to produce multiples of a single design with accuracy and speed.  

How long does the production process take from start to finish?

This explanation does not include any lead time we are currently experiencing. The development period for new clients typically takes 2-4 months but depends on the project and the amount of development the client requests. Once the development process is complete we schedule a production run. The production run timeline is subject to current lead times and the number of units being produced. Our average production rate for the first 3 months of production is 50 units per month. The process of developing a new product is not an exact science. It's all about patience and working together to understand this crazy thing called clay.

Can I order samples of your clay and glaze options?

Yep! First, take a look at our Material Library to view our available options. Once you know what you'd like to see in person, email us at [email protected] for a swatch request form.

You don't have the slip/clay/glaze that I want to work with. Are there other options?

We do accept out-of-house materials but with a few requirements. Check out our Custom Material Guide for more information. This covers custom options as well.

What is a RAM press and how does it work?

A RAM press, or any ceramic press for that matter, distributes clay in a mold through the application of pressure. The press brings a top and bottom mold part together to form a finished piece. Because the form is pressed the thickness of the piece is determined by the press settings and each respective half must be free of undercuts. It's a great way to produce pieces quickly.

What type of glue works best with ceramic surfaces?

We get this question a ton and since we're all about making our client's lives easier, here you go. We use this stuff and it's great: 3M Scotch-Weld Concrete Repair, DP 600. We wish it was a more exciting question, like 'What's your favorite ramen place in town?' but we're making it work.

I'm interested in ceramic decals. Can I buy them from you? Can you apply them to my production project?

Can you buy them from us? Nope, sorry! Can we apply and fire them for you? Yes! There is an additional cost for application which varies on the complexity and size of the decal. Take a look at our Custom Material Guide for more information on who you can contact to get your decals printed.

Do you offer sample or prototype work before I commit to a production run?

Great question! We require each new project to complete our detailed internal development process. This process ensures that your design is viable for production at Mudshark Studios. Depending on the type of project you may encounter our product development process or our production development process. The former option is only available to slipcasting production projects. These processes will include samples for you to approve before the full production run. You may reference our Process Reference Guide for more information.

What are undercuts?

An undercut is an indentation or protrusion in a shape that will prevent a form from releasing from a mold. Clay/slip will fill an undercut and prevent the cast from freely releasing from the mold without breakage or distortion.

What is draft?

In our terms, draft is the angle added to a vertical plane to ease the removal of a form from a mold. Let's say you had a planter design with vertical walls. A 2 part mold would be required in order to release the model from the mold. Same goes with releasing the master from the rubber. Now if you added draft to those vertical walls, increasing the diameter of the opening by 2 degrees more than the diameter of the base, you could successfully release those parts and reduce stress on your castings. The benefits, you ask? No seamlines, less work time, fewer mold parts and reduced mold costs. Who's in?

Are there any design limitations that I should keep in mind?

Yes! Designs intended to be slipcast need to have uniform thickness throughout the design. If you need to capture varying thickness in a design the RAM press will be your only option, however not all designs are compatible with the press. Our minimum wall thickness is typically 1/4 inch, but this will depend on the size of the piece and production method for your project.

I'd prefer to provide my own model. What materials are acceptable?

Any rigid material that is non-porous and can withstand direct heat. Plaster will heat up to about 140 degrees Fahrenheit during the mold fabrication process..

What material do you use to print 3D models?

The primary 3D printed material we use is High Temperature Polylactic Acid, or PLA for short, which is a ridged Bioplastic made from renewable resources such as corn or sugarcane. The printed model can exist in normal indoor conditions for years or even decades, but can also be recycled or even composted as it is biodegradable! A less common material we use is Thermoplastic Polyurethane better known as TPU. This plastic allows for us to make 3D prints that are flexible, potentially eliminating the need for costly rubber molds to be made.

Where do you recommend I order embossing/underglaze stamps?

We currently provide emboss stamp print services, so please feel welcome to place your order through us. For underglaze stamps we recommend that you contact A to Z Stamps. When ordering an underglaze stamp, please make sure to request a rubber stamp that includes a foam layer with a rocker-style press.

How does Mudshark protect my intellectual property?

As a private label manufacturer, we take the protection of your intellectual property seriously. Upon hire, Mudshark employees sign a non-disclosure agreement which encompasses each product that we manufacture. Project information is shared with our production team on an as-needed basis only. Information is never shared between clients, and we will not accept new projects with an overt similarity to designs we currently produce or have produced in the past.
Furthermore, we will never disclose any confidential or proprietary information without prior written consent from our clients, and will never share your information with a third party.

Do you offer price incentives for increased order quantities?

In an effort to make our lowest price accessible to all customers regardless of the order quantity, we do not offer pricing incentives for orders greater than 100 units.

What is your minimum order quantity (MOQ)?

We do not have an order minimum at this time, however our pricing is calculated to reflect orders of 100 units or more. Orders of less than 100 units are subject to increased pricing.

How much do you charge for orders less than 100 units?

1 to 25 units: Completed at shop rate of $80/hr; no per unit cost.
26 to 49 units: Unit rate is 1.56x the 100+ unit rate.
50 to 99 units: Unit rate is 1.2x the 100+ unit rate

I'm interested in production services. What are your unit costs?

Unit prices are calculated with several factors in mind, such as the shape, size, and complexity of your design. Glazed pieces start at $16.00 per unit.

What other costs are associated with production projects?

For new production projects, please anticipate model, mold, and development costs in addition to the per unit costs. Development is $80/hour, and all new projects are required to submit a $800 development deposit to cover development work time.

How much do slipcasting molds cost?

Mold pricing is contingent on several factors: the complexity of the mold or what we refer to as the number of mold parts, the size of the mold, and the total seamline distance. Mold costs vary depending on the type of mold, too. Master molds start at $200, rubber molds start at $310, and production molds at $25/mold. Keep in mind that your mold costs are impacted by your unique design-- we need to review your design in detail before we can provide an estimate.

How much do RAM press molds cost?

RAM mold pricing is contingent on the size of the mold-- height, width, and depth. Costs start at $2,000 and include 2 tooling rings, a top and bottom case, a RAM master mold, rubber mold, and working mold.

How much do you charge for 3D prints?

Model pricing is contingent on the design and size of the piece you want to produce. Typical pricing starts at $300 , but can range upwards of $1,500 depending on the size and complexity of your piece. We welcome you to provide your own model work if this option is available to you.

Is shipping cost included?

Shipping, handling, and packaging costs are separate from the unit cost. Shipping costs are based on the weight and size of your shipment so we cannot provide an estimate before the project is produced, but packaging costs are typically 10% of the unit cost per unit.

Where are you located?

Our studio is located in the Kerns neighborhood of Portland, Oregon.

Can I visit? How about a tour?

We'd love for you to visit but all visits and tours require an appointment. If you are interested in scheduling a tour please email us at [email protected]. If possible, please do your best to inquire 2 weeks in advance as we are often unable to accommodate tours with less notice.

What services do you offer?

We offer a wide range of services all catered to support the ceramic manufacturing process. These services include 3D model printing, mold making, ceramic production, glass slump molds, educational workshops, and business consultations. If you are interested in a service that we haven't listed, either shoot us an email or check out the next question. Workshops aren't available yet but they're on their way!

What services do you not offer?

We do not offer glass production or materials, silicone or resin mold work, or ceramic repair services of existing work at this time.

We'd like to feature you in our magazine/article/cool marketing opportunity. Who do I contact for press information?

Please submit your press inquiries to [email protected] and we'll get you squared away!

Will you sign an NDA?

As a private label manufacturer we take the protection of your confidential and proprietary information seriously. Upon hire all Mudshark employees sign a non-disclosure agreement that applies to any products that Mudshark will manufacture or has manufactured. Project information is shared with the production team on a need-to-know basis only. We do not sign additional NDAs at this time.

I'm looking for business advice-- do you provide consultation services?

If you're are looking to take your studio to the next step level, or if you're just genuinely interested in what we do and how we do it, we're glad to share our insight and experiences with you. However, please keep in mind that as a small studio with a business to run we do need to charge for these services to help keep us afloat. Our consultation service fee is $125/hour. Mobile (local businesses only) consultations require a 4 hour minimum appointment. You direct the experience. Let us know what you need and we'll make it happen!

Are you hiring? How do I apply?

We are not currently hiring but we are always glad to accept your resume and will contact you should our position change. To apply, please visit our Contact page to view and submit our application.

What's your favorite place to get ramen in Portland?

We thought you'd never ask! We're smitten with Ichiza Kitchen. Bring us some and we just might be friends for life.